SlideShare ist ein Scribd-Unternehmen logo
1 von 77
PROTEOMICS Ms.ruchiyadavlectureramity institute of biotechnologyamity universitylucknow(up)
introduction –what is proteomics? Definition:- The identification, characterization and quantification of all proteins involved in a particular pathway, organelle, cell, tissue, organ or organism that can be studied in concert to provide accurate and comprehensive data about that system.”
PROTEOMICS The study of the expression, location, interaction, function and structure of all the proteins in a given cell or organism Functional Proteomics Expressional Proteomics Structural Proteomics
PROTEOMICS Functional proteomics: What is the function of each product of the 30,000 human genes where do protein localize, what do they interact with.( Interactomics) how are they modified (PTM) Structural proteomics: What is the 3D structure of proteins and multi-protein machines? Expression proteomics: What differences in protein expression levels accompany certain  , Aspects of a cell’s physiology? (normal or pathological)
PROTEOME
Typical Proteome Experiment
Methods used in proteomics
Fundamental methods used in proteomics
Methods for Protein identification
The identities of proteins Size: molecular weight (utilized in 2-DE) Charge: pI (utilized in 2-DE) Hydrophobicity
Major techniques in modern proteomics  Two dimensional electrophoresis, 2-DE  Mass spectrometry
Global profiling proteomics Identification of protein markers from patient samples
Find the different protein spots on 2-D gels
how is MS used in proteomics ?
Perspective for MS based Proteomics
Principle of mass spectrometry in proteomics
Mass spectrometry:principle Masses of Amino Acid Residues
Peptide Fragmentation Collision Induced Dissociation H+ H...-HN-CH-CO   .  .   .NH-CH-CO-NH-CH-CO-…OH Ri-1 Ri Ri+1 Prefix Fragment Suffix Fragment ,[object Object]
The types of fragment ions observed in an MS/MS spectrum depend on many factors including primary sequence, the amount of internal energy, how the energy was introduced, charge state, etc.,[object Object]
Breaking Protein into Peptides and Peptides into Fragment Ions(ms/ms) Proteases, e.g. trypsin, break protein into peptides. A Tandem Mass Spectrometer further breaks the peptides down into fragment ions and measures the mass of each piece. Mass Spectrometer accelerates the fragmented ions; heavier ions accelerate slower than lighter ones. Mass Spectrometer measure mass/chargeratio of an ion.
N- and C-terminal Peptides P A G N F A P G N F A N P G F C-terminal peptides N-terminal peptides A N F P G P A N F G
Terminal peptides and ion types Peptide H2O P N G F Mass (D)    57  +  97  + 147 + 114  = 415 without G F N   Peptide H2O P Mass (D)    57  +  97  + 147 + 114 – 18 = 397
Peptide Fragmentation Peptide: S-G-F-L-E-E-D-E-L-K 24
G V D L K L 57 Da = ‘G’ K   D V G  99 Da = ‘V’ H2O D Mass Spectra mass 0 ,[object Object]
Prefix and Suffix Fragments.
Fragments with neutral losses(-H2O, -NH3)
Noise and missing peaks.,[object Object]
Commonly used Mass Spectrometer in Proteomics MALDI-TOF Matrix Assisted Laser Desorption Ionization Time Of Flight ESI tandem MS (with HPLC, LC tandem MS or LC MS/MS) Electro Spray Ionization Mass Spectrometry
Mass spectrometry used to sequence short stretches of polypeptide
Single Stage MS MS
  Tandem Mass Spectrometry(MS/MS) Precursor selection 30
 Tandem Mass Spectrometry (MS/MS) Precursor selection +  collision induced dissociation (CID) MS/MS
Tandem mass spectrometry
MS FOR PEPTIDE MASS AND SEQUENCE DETECTION MALDI-TOF
Typical result from MALDI-Tof (spectrum)
High throughput technique:2D electrophoresis + Mass spectrometry Separation identification
Basic concept for routine protein analysis
Peptide mass fingerprinting (PMF)
Peptide mass fingerprinting (PMF)
   Principles of Fingerprinting* SequenceMass (M+H)Tryptic Fragments acedfhsak dfgeasdfpk ivtmeeewendadnfek gwfe acek dfhsadfgeasdfpk ivtmeeewenk dadnfeqwfe acedfhsadfgek asdfpk ivtmeeewendak dnfegwfe >Protein 1 acedfhsakdfqea sdfpkivtmeeewe ndadnfekqwfe >Protein 2 acekdfhsadfqea sdfpkivtmeeewe nkdadnfeqwfe >Protein 3 acedfhsadfqeka sdfpkivtmeeewe ndakdnfeqwfe 4842.05 4842.05 4842.05
Principles of Fingerprinting SequenceMass (M+H)Mass Spectrum >Protein 1 acedfhsakdfqea sdfpkivtmeeewe ndadnfekqwfe >Protein 2 acekdfhsadfqea sdfpkivtmeeewe nkdadnfeqwfe >Protein 3 acedfhsadfqeka sdfpkivtmeeewe ndakdnfeqwfe 4842.05 4842.05 4842.05
Data analysis of ms/ms method
Peptide mass fingerprinting (PMF) or mapping
Mass spectrum mapping Top spectrum depicts a theoretical mass spectrum, as might be generated by a sequence search algorithm, matching an actual peptide MS/MS spectrum (bottom).
Computer prog. search databases that contain information
Peptide analysis
Pmf on web Mascot www.matrixscience.com ProFound http://129.85.19.192/profound_bin/WebProFound.exe MOWSE http://srs.hgmp.mrc.ac.uk/cgi-bin/mowse PeptideSearch http://www.narrador.embl-heidelberg.de/GroupPages/Homepage.html PeptIdent http://us.expasy.org/tools/peptident.html
mascot
mascot
Ptm identification
Expression proteomics Separation, quantification and identification of large numbers of proteins from biological specimens 2D gel electophoresis Mass Spec analysis
Ms/ms for post translational modification PTM-specific mass increments of peptides and amino acid residues or diagnostic fragment ions in mass spectra reveal the presence of PTMs. The MS spectrum is acquired to determine the molecular mass of the peptides. Next, peptides are in turn selected for MS/MS. Fragmentation of the peptide amide bond produces a set of fragment ions that generate a l readout of the sequence in the tandem mass spectrum. The presence of a PTM will change the mass of the modified amino acid residue and of the peptide.  MS/ MS often reveals the mass of the PTM and the identity and position of the modified amino acid residue.
Tandem mass spectrometry (MS/MS) for mapping posttranslational modifications
List of modification and their properties
Ptm identification tools
Protein –protein interaction
Ppi methods
Genomic Context Phylogenetic profiles Conservation of gene neighborhood Gene Fusion Similarity of phylogenetic trees Correlated mutations
1.Phylogenetic Profile Based on the pattern of the presence or absence of a given gene in a set of genomes A profile is constructed for each protein (Prot a–Prot d), recording its presence (1) or absence (0) in a set of organisms Pairs of proteins with identical (or similar) phylogenetic profiles are predicted to interact (Prot a and Prot c in this case)
2.Gene cluster and gene neighborhood methods, Proteins whose genes are physically close in the genomes of various organisms are predicted to interact. B
3.GENE FUSION Rosetta Stone method: The Rosetta Stone approach infers protein interactions from protein sequences in different genomes .  It is based on the observation that some interacting proteins/domains have homologs in other genomes that are fused into one protein chain, a so-called Rosetta Stone protein
REDUCED MSA(4,5) To obtain a quantitative indicator of the interaction between two proteins (Prot a and Prot b), the MSAs of both proteins are reduced to the set of  organisms common to the two proteins (Org 1–Org 5).  Each of the reduced alignments is used to construct the corresponding intersequence distance matrix.
4. Similarity of phylogenetic trees (Mirrortree) Matrices are commonly used to construct the corresponding phylogenetic trees.  Linear correlation between these distance matrices is calculated. High correlation values are interpreted as indicative of the similarity between phylogenetic trees and hence are taken as predicted interactions.
5.Correlated mutations
5.Correlated mutations A correlation coefficient is calculated for every pair of residues.  The pairs are divided into three sets:  two for the intraprotein pairs (Caa and Cbb; pairs of positions within Prot a and within Prot b) and  one for the interprotein pairs (Cab; one position from Prot a and one from Prot b). The distributions of correlation values are recorded for these three sets.  The ‘interaction index’ is calculated by comparing the distribution of interprotein correlations with the two distributions of intraprotein correlations
6. Classification methods/RDF method Five different features/domains are used  Each interacting protein pair is encoded as a string of 0, 1, and 2.  The decision trees are constructed based on the training set of interacting protein pairs . Decisions are made if proteins under the question interact or not (‘‘yes’’ for interacting, ‘‘no’’ for non-interacting).
PPI DATABASE
Protein microarray
types of protein microarrays Three types of protein microarrays are currently used to study the biochemical activities of proteins:  Analytical microarrays,  Functional microarrays, and  Reverse phase microarrays
Analytical microarrays Different types of ligands, including antibodies, antigens, DNA or RNA aptamers, carbohydrates or small molecules, with high affinity and specificity, are spotted down onto a derivatized surface.  Protein samples from two biological states to be compared are separately labelled with red or green fluorescent dyes, mixed, and incubated with the chips. Spots in red or green colour identify an excess of proteins from one state over the other. These types of microarrays can be used to monitor differential expression profiles and for clinical diagnostics. Examples include profiling responses to environmental stress and healthy versus disease tissues
Functional protein microarrays Native proteins or peptides are individually purified or synthesized using high-throughput approaches and arrayed onto a suitable surface to form the functional protein microarrays.  These chips are used to analyse protein activities, binding properties and post-translational modifications.  functional protein microarrays can be used to identify the substrates of enzymes of interest.  This class of chips is particularly useful in drug and drug-target identification and in building biological networks
Analytical versus functional protein microarrays.
Functional protein microarrays Functional protein microarrays differ from analytical arrays in that functional protein arrays are composed of arrays containing full-length functional proteins or protein domains. These protein chips are used to study the biochemical activities of an entire proteome in a single experiment.  They are used to study numerous protein interactions, such as protein-protein, protein-DNA, protein-RNA, protein-phospholipid, and protein-small molecule interactions
reverse phase protein microarray (RPA) In RPA, cells are isolated from various tissues of interest and are lysed.  The lysate is arrayed onto a nitrocellulose slide using a contact pin microarrayer. The slides are then probed with antibodies against the target protein of interest, and the antibodies are typically detected with chemiluminescent, fluorescent, or colorimetric assays.
RPA RPAs allow for the determination of the presence of altered proteins that may be the result of disease.  Specifically, post-translational modifications, which are typically altered as a result of disease, can be detected using RPAs

Weitere ähnliche Inhalte

Was ist angesagt?

Functional proteomics, methods and tools
Functional proteomics, methods and toolsFunctional proteomics, methods and tools
Functional proteomics, methods and toolsKAUSHAL SAHU
 
Protein micro array
Protein micro arrayProtein micro array
Protein micro arraykrupa sagar
 
Protein array, types and application
Protein array, types and applicationProtein array, types and application
Protein array, types and applicationKAUSHAL SAHU
 
Metabolomics- concepts and applications
Metabolomics- concepts and applicationsMetabolomics- concepts and applications
Metabolomics- concepts and applicationsAnup Ray
 
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...Prasenjit Mitra
 
Applications of genomics and proteomics ppt
Applications of genomics and  proteomics pptApplications of genomics and  proteomics ppt
Applications of genomics and proteomics pptIbad khan
 
Proteomics and its applications in phytopathology
Proteomics and its applications in phytopathologyProteomics and its applications in phytopathology
Proteomics and its applications in phytopathologyAbhijeet Kashyap
 
Genes, Genomics and Proteomics
Genes, Genomics and Proteomics Genes, Genomics and Proteomics
Genes, Genomics and Proteomics Garry D. Lasaga
 
A Brief Introduction to Metabolomics
A Brief Introduction to Metabolomics A Brief Introduction to Metabolomics
A Brief Introduction to Metabolomics Ranjith Raj V
 
Motif & Domain
Motif & DomainMotif & Domain
Motif & DomainAnik Banik
 
NMR of protein
NMR of proteinNMR of protein
NMR of proteinJiya Ali
 
Protein-Protein Interactions (PPIs)
Protein-Protein Interactions (PPIs)Protein-Protein Interactions (PPIs)
Protein-Protein Interactions (PPIs)Sai Ram
 
Functional genomics
Functional genomicsFunctional genomics
Functional genomicsajay301
 
Introduction to proteomics
Introduction to proteomicsIntroduction to proteomics
Introduction to proteomicsShryli Shreekar
 
Genomics and proteomics in drug discovery and development
Genomics and proteomics in drug discovery and developmentGenomics and proteomics in drug discovery and development
Genomics and proteomics in drug discovery and developmentSuchittaU
 

Was ist angesagt? (20)

Functional proteomics, methods and tools
Functional proteomics, methods and toolsFunctional proteomics, methods and tools
Functional proteomics, methods and tools
 
Protein micro array
Protein micro arrayProtein micro array
Protein micro array
 
Protein array, types and application
Protein array, types and applicationProtein array, types and application
Protein array, types and application
 
Metabolomics- concepts and applications
Metabolomics- concepts and applicationsMetabolomics- concepts and applications
Metabolomics- concepts and applications
 
Genomics
GenomicsGenomics
Genomics
 
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...
Genomics, Transcriptomics, Proteomics, Metabolomics - Basic concepts for clin...
 
Applications of genomics and proteomics ppt
Applications of genomics and  proteomics pptApplications of genomics and  proteomics ppt
Applications of genomics and proteomics ppt
 
Proteomics and its applications in phytopathology
Proteomics and its applications in phytopathologyProteomics and its applications in phytopathology
Proteomics and its applications in phytopathology
 
Genes, Genomics and Proteomics
Genes, Genomics and Proteomics Genes, Genomics and Proteomics
Genes, Genomics and Proteomics
 
Applications of Proteomics Science
Applications of Proteomics ScienceApplications of Proteomics Science
Applications of Proteomics Science
 
A Brief Introduction to Metabolomics
A Brief Introduction to Metabolomics A Brief Introduction to Metabolomics
A Brief Introduction to Metabolomics
 
Motif & Domain
Motif & DomainMotif & Domain
Motif & Domain
 
NMR of protein
NMR of proteinNMR of protein
NMR of protein
 
Structural genomics
Structural genomicsStructural genomics
Structural genomics
 
Protein-Protein Interactions (PPIs)
Protein-Protein Interactions (PPIs)Protein-Protein Interactions (PPIs)
Protein-Protein Interactions (PPIs)
 
RNA-Seq
RNA-SeqRNA-Seq
RNA-Seq
 
Peptide Mass Fingerprinting
Peptide Mass FingerprintingPeptide Mass Fingerprinting
Peptide Mass Fingerprinting
 
Functional genomics
Functional genomicsFunctional genomics
Functional genomics
 
Introduction to proteomics
Introduction to proteomicsIntroduction to proteomics
Introduction to proteomics
 
Genomics and proteomics in drug discovery and development
Genomics and proteomics in drug discovery and developmentGenomics and proteomics in drug discovery and development
Genomics and proteomics in drug discovery and development
 

Ähnlich wie Proteomics

Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...
Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...
Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...Keiji Takamoto
 
Proteomics in VSC for crop improvement programme
Proteomics in VSC for crop improvement programmeProteomics in VSC for crop improvement programme
Proteomics in VSC for crop improvement programmeSumanthBT1
 
1.proteomics coursework-3 dec2012-aky
1.proteomics coursework-3 dec2012-aky1.proteomics coursework-3 dec2012-aky
1.proteomics coursework-3 dec2012-akyAmit Yadav
 
Protein Qualitative Analysis Services
Protein Qualitative Analysis ServicesProtein Qualitative Analysis Services
Protein Qualitative Analysis ServicesCreative Proteomics
 
Targeted and Discovery Proteomics
Targeted and Discovery ProteomicsTargeted and Discovery Proteomics
Targeted and Discovery ProteomicsCreative Proteomics
 
“Proteomics” to study genes and genomes
“Proteomics” to study genes and genomes“Proteomics” to study genes and genomes
“Proteomics” to study genes and genomesNazish_Nehal
 
Methods to Detect Protein-Protein Interaction
Methods to Detect Protein-Protein InteractionMethods to Detect Protein-Protein Interaction
Methods to Detect Protein-Protein InteractionCreative Proteomics
 
Proteomics, definatio , general concept, signficance
Proteomics,  definatio , general concept, signficanceProteomics,  definatio , general concept, signficance
Proteomics, definatio , general concept, signficanceKAUSHAL SAHU
 
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICS
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICSSTRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICS
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICSSHEETHUMOLKS
 
MULISA : A New Strategy for Discovery of Protein Functional Motifs and Residues
MULISA : A New Strategy for Discovery of Protein Functional Motifs and ResiduesMULISA : A New Strategy for Discovery of Protein Functional Motifs and Residues
MULISA : A New Strategy for Discovery of Protein Functional Motifs and Residuescsandit
 
Prediction of protein function
Prediction of protein functionPrediction of protein function
Prediction of protein functionLars Juhl Jensen
 
Proteomics
ProteomicsProteomics
ProteomicsHNGU
 
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...Discrimination of symbiotic/parasitic bacterial type III secretion system eff...
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...Y-h Taguchi
 
Research presentation-wd
Research presentation-wdResearch presentation-wd
Research presentation-wdWagied Davids
 
Proteomics and protein-protein interaction
Proteomics  and protein-protein interactionProteomics  and protein-protein interaction
Proteomics and protein-protein interactionSenthilkumarV25
 

Ähnlich wie Proteomics (20)

Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...
Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...
Theoretical evaluation of shotgun proteomic analysis strategies; Peptide obse...
 
proteomics
 proteomics proteomics
proteomics
 
Proteomics in VSC for crop improvement programme
Proteomics in VSC for crop improvement programmeProteomics in VSC for crop improvement programme
Proteomics in VSC for crop improvement programme
 
1.proteomics coursework-3 dec2012-aky
1.proteomics coursework-3 dec2012-aky1.proteomics coursework-3 dec2012-aky
1.proteomics coursework-3 dec2012-aky
 
Proteomics
ProteomicsProteomics
Proteomics
 
Protein Qualitative Analysis Services
Protein Qualitative Analysis ServicesProtein Qualitative Analysis Services
Protein Qualitative Analysis Services
 
Targeted and Discovery Proteomics
Targeted and Discovery ProteomicsTargeted and Discovery Proteomics
Targeted and Discovery Proteomics
 
“Proteomics” to study genes and genomes
“Proteomics” to study genes and genomes“Proteomics” to study genes and genomes
“Proteomics” to study genes and genomes
 
Methods to Detect Protein-Protein Interaction
Methods to Detect Protein-Protein InteractionMethods to Detect Protein-Protein Interaction
Methods to Detect Protein-Protein Interaction
 
Proteomics, definatio , general concept, signficance
Proteomics,  definatio , general concept, signficanceProteomics,  definatio , general concept, signficance
Proteomics, definatio , general concept, signficance
 
Yasset perezriverol csi2011
Yasset perezriverol csi2011Yasset perezriverol csi2011
Yasset perezriverol csi2011
 
MpM
MpMMpM
MpM
 
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICS
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICSSTRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICS
STRUCTURAL GENOMICS, FUNCTIONAL GENOMICS, COMPARATIVE GENOMICS
 
MULISA : A New Strategy for Discovery of Protein Functional Motifs and Residues
MULISA : A New Strategy for Discovery of Protein Functional Motifs and ResiduesMULISA : A New Strategy for Discovery of Protein Functional Motifs and Residues
MULISA : A New Strategy for Discovery of Protein Functional Motifs and Residues
 
Prediction of protein function
Prediction of protein functionPrediction of protein function
Prediction of protein function
 
www.ijerd.com
www.ijerd.comwww.ijerd.com
www.ijerd.com
 
Proteomics
ProteomicsProteomics
Proteomics
 
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...Discrimination of symbiotic/parasitic bacterial type III secretion system eff...
Discrimination of symbiotic/parasitic bacterial type III secretion system eff...
 
Research presentation-wd
Research presentation-wdResearch presentation-wd
Research presentation-wd
 
Proteomics and protein-protein interaction
Proteomics  and protein-protein interactionProteomics  and protein-protein interaction
Proteomics and protein-protein interaction
 

Mehr von ruchibioinfo

Mehr von ruchibioinfo (7)

Sequence comparison techniques
Sequence comparison techniquesSequence comparison techniques
Sequence comparison techniques
 
RNA interference
RNA interferenceRNA interference
RNA interference
 
Microarray
MicroarrayMicroarray
Microarray
 
Genome Mapping
Genome MappingGenome Mapping
Genome Mapping
 
Human genome project
Human genome projectHuman genome project
Human genome project
 
Genome origin
Genome originGenome origin
Genome origin
 
Genome evolution
Genome evolutionGenome evolution
Genome evolution
 

Proteomics

  • 1. PROTEOMICS Ms.ruchiyadavlectureramity institute of biotechnologyamity universitylucknow(up)
  • 2. introduction –what is proteomics? Definition:- The identification, characterization and quantification of all proteins involved in a particular pathway, organelle, cell, tissue, organ or organism that can be studied in concert to provide accurate and comprehensive data about that system.”
  • 3. PROTEOMICS The study of the expression, location, interaction, function and structure of all the proteins in a given cell or organism Functional Proteomics Expressional Proteomics Structural Proteomics
  • 4. PROTEOMICS Functional proteomics: What is the function of each product of the 30,000 human genes where do protein localize, what do they interact with.( Interactomics) how are they modified (PTM) Structural proteomics: What is the 3D structure of proteins and multi-protein machines? Expression proteomics: What differences in protein expression levels accompany certain , Aspects of a cell’s physiology? (normal or pathological)
  • 7. Methods used in proteomics
  • 8. Fundamental methods used in proteomics
  • 9. Methods for Protein identification
  • 10. The identities of proteins Size: molecular weight (utilized in 2-DE) Charge: pI (utilized in 2-DE) Hydrophobicity
  • 11. Major techniques in modern proteomics Two dimensional electrophoresis, 2-DE Mass spectrometry
  • 12. Global profiling proteomics Identification of protein markers from patient samples
  • 13. Find the different protein spots on 2-D gels
  • 14. how is MS used in proteomics ?
  • 15. Perspective for MS based Proteomics
  • 16. Principle of mass spectrometry in proteomics
  • 17. Mass spectrometry:principle Masses of Amino Acid Residues
  • 18.
  • 19.
  • 20.
  • 21. Breaking Protein into Peptides and Peptides into Fragment Ions(ms/ms) Proteases, e.g. trypsin, break protein into peptides. A Tandem Mass Spectrometer further breaks the peptides down into fragment ions and measures the mass of each piece. Mass Spectrometer accelerates the fragmented ions; heavier ions accelerate slower than lighter ones. Mass Spectrometer measure mass/chargeratio of an ion.
  • 22. N- and C-terminal Peptides P A G N F A P G N F A N P G F C-terminal peptides N-terminal peptides A N F P G P A N F G
  • 23. Terminal peptides and ion types Peptide H2O P N G F Mass (D) 57 + 97 + 147 + 114 = 415 without G F N Peptide H2O P Mass (D) 57 + 97 + 147 + 114 – 18 = 397
  • 24. Peptide Fragmentation Peptide: S-G-F-L-E-E-D-E-L-K 24
  • 25.
  • 26. Prefix and Suffix Fragments.
  • 27. Fragments with neutral losses(-H2O, -NH3)
  • 28.
  • 29. Commonly used Mass Spectrometer in Proteomics MALDI-TOF Matrix Assisted Laser Desorption Ionization Time Of Flight ESI tandem MS (with HPLC, LC tandem MS or LC MS/MS) Electro Spray Ionization Mass Spectrometry
  • 30. Mass spectrometry used to sequence short stretches of polypeptide
  • 32. Tandem Mass Spectrometry(MS/MS) Precursor selection 30
  • 33. Tandem Mass Spectrometry (MS/MS) Precursor selection + collision induced dissociation (CID) MS/MS
  • 35. MS FOR PEPTIDE MASS AND SEQUENCE DETECTION MALDI-TOF
  • 36. Typical result from MALDI-Tof (spectrum)
  • 37. High throughput technique:2D electrophoresis + Mass spectrometry Separation identification
  • 38. Basic concept for routine protein analysis
  • 41. Principles of Fingerprinting* SequenceMass (M+H)Tryptic Fragments acedfhsak dfgeasdfpk ivtmeeewendadnfek gwfe acek dfhsadfgeasdfpk ivtmeeewenk dadnfeqwfe acedfhsadfgek asdfpk ivtmeeewendak dnfegwfe >Protein 1 acedfhsakdfqea sdfpkivtmeeewe ndadnfekqwfe >Protein 2 acekdfhsadfqea sdfpkivtmeeewe nkdadnfeqwfe >Protein 3 acedfhsadfqeka sdfpkivtmeeewe ndakdnfeqwfe 4842.05 4842.05 4842.05
  • 42. Principles of Fingerprinting SequenceMass (M+H)Mass Spectrum >Protein 1 acedfhsakdfqea sdfpkivtmeeewe ndadnfekqwfe >Protein 2 acekdfhsadfqea sdfpkivtmeeewe nkdadnfeqwfe >Protein 3 acedfhsadfqeka sdfpkivtmeeewe ndakdnfeqwfe 4842.05 4842.05 4842.05
  • 43. Data analysis of ms/ms method
  • 44. Peptide mass fingerprinting (PMF) or mapping
  • 45. Mass spectrum mapping Top spectrum depicts a theoretical mass spectrum, as might be generated by a sequence search algorithm, matching an actual peptide MS/MS spectrum (bottom).
  • 46. Computer prog. search databases that contain information
  • 48. Pmf on web Mascot www.matrixscience.com ProFound http://129.85.19.192/profound_bin/WebProFound.exe MOWSE http://srs.hgmp.mrc.ac.uk/cgi-bin/mowse PeptideSearch http://www.narrador.embl-heidelberg.de/GroupPages/Homepage.html PeptIdent http://us.expasy.org/tools/peptident.html
  • 52. Expression proteomics Separation, quantification and identification of large numbers of proteins from biological specimens 2D gel electophoresis Mass Spec analysis
  • 53. Ms/ms for post translational modification PTM-specific mass increments of peptides and amino acid residues or diagnostic fragment ions in mass spectra reveal the presence of PTMs. The MS spectrum is acquired to determine the molecular mass of the peptides. Next, peptides are in turn selected for MS/MS. Fragmentation of the peptide amide bond produces a set of fragment ions that generate a l readout of the sequence in the tandem mass spectrum. The presence of a PTM will change the mass of the modified amino acid residue and of the peptide. MS/ MS often reveals the mass of the PTM and the identity and position of the modified amino acid residue.
  • 54. Tandem mass spectrometry (MS/MS) for mapping posttranslational modifications
  • 55. List of modification and their properties
  • 59. Genomic Context Phylogenetic profiles Conservation of gene neighborhood Gene Fusion Similarity of phylogenetic trees Correlated mutations
  • 60. 1.Phylogenetic Profile Based on the pattern of the presence or absence of a given gene in a set of genomes A profile is constructed for each protein (Prot a–Prot d), recording its presence (1) or absence (0) in a set of organisms Pairs of proteins with identical (or similar) phylogenetic profiles are predicted to interact (Prot a and Prot c in this case)
  • 61. 2.Gene cluster and gene neighborhood methods, Proteins whose genes are physically close in the genomes of various organisms are predicted to interact. B
  • 62. 3.GENE FUSION Rosetta Stone method: The Rosetta Stone approach infers protein interactions from protein sequences in different genomes . It is based on the observation that some interacting proteins/domains have homologs in other genomes that are fused into one protein chain, a so-called Rosetta Stone protein
  • 63. REDUCED MSA(4,5) To obtain a quantitative indicator of the interaction between two proteins (Prot a and Prot b), the MSAs of both proteins are reduced to the set of organisms common to the two proteins (Org 1–Org 5). Each of the reduced alignments is used to construct the corresponding intersequence distance matrix.
  • 64. 4. Similarity of phylogenetic trees (Mirrortree) Matrices are commonly used to construct the corresponding phylogenetic trees. Linear correlation between these distance matrices is calculated. High correlation values are interpreted as indicative of the similarity between phylogenetic trees and hence are taken as predicted interactions.
  • 66. 5.Correlated mutations A correlation coefficient is calculated for every pair of residues. The pairs are divided into three sets: two for the intraprotein pairs (Caa and Cbb; pairs of positions within Prot a and within Prot b) and one for the interprotein pairs (Cab; one position from Prot a and one from Prot b). The distributions of correlation values are recorded for these three sets. The ‘interaction index’ is calculated by comparing the distribution of interprotein correlations with the two distributions of intraprotein correlations
  • 67. 6. Classification methods/RDF method Five different features/domains are used Each interacting protein pair is encoded as a string of 0, 1, and 2. The decision trees are constructed based on the training set of interacting protein pairs . Decisions are made if proteins under the question interact or not (‘‘yes’’ for interacting, ‘‘no’’ for non-interacting).
  • 70. types of protein microarrays Three types of protein microarrays are currently used to study the biochemical activities of proteins: Analytical microarrays, Functional microarrays, and Reverse phase microarrays
  • 71. Analytical microarrays Different types of ligands, including antibodies, antigens, DNA or RNA aptamers, carbohydrates or small molecules, with high affinity and specificity, are spotted down onto a derivatized surface. Protein samples from two biological states to be compared are separately labelled with red or green fluorescent dyes, mixed, and incubated with the chips. Spots in red or green colour identify an excess of proteins from one state over the other. These types of microarrays can be used to monitor differential expression profiles and for clinical diagnostics. Examples include profiling responses to environmental stress and healthy versus disease tissues
  • 72. Functional protein microarrays Native proteins or peptides are individually purified or synthesized using high-throughput approaches and arrayed onto a suitable surface to form the functional protein microarrays. These chips are used to analyse protein activities, binding properties and post-translational modifications. functional protein microarrays can be used to identify the substrates of enzymes of interest. This class of chips is particularly useful in drug and drug-target identification and in building biological networks
  • 73. Analytical versus functional protein microarrays.
  • 74. Functional protein microarrays Functional protein microarrays differ from analytical arrays in that functional protein arrays are composed of arrays containing full-length functional proteins or protein domains. These protein chips are used to study the biochemical activities of an entire proteome in a single experiment. They are used to study numerous protein interactions, such as protein-protein, protein-DNA, protein-RNA, protein-phospholipid, and protein-small molecule interactions
  • 75. reverse phase protein microarray (RPA) In RPA, cells are isolated from various tissues of interest and are lysed. The lysate is arrayed onto a nitrocellulose slide using a contact pin microarrayer. The slides are then probed with antibodies against the target protein of interest, and the antibodies are typically detected with chemiluminescent, fluorescent, or colorimetric assays.
  • 76. RPA RPAs allow for the determination of the presence of altered proteins that may be the result of disease. Specifically, post-translational modifications, which are typically altered as a result of disease, can be detected using RPAs
  • 77.