In medicine, proteopathy refers to a class of diseases in which certain proteins become structurally abnormal, and thereby disrupt the fuction of cells, tissues and organs of the body. Often the proteins fail to fold into their normal configuration; in this misfolded state, the proteins can become toxic in some way (a gain of toxic function) or they can lose their normal function. The proteopathies (also known as proteinopathies, protein conformational disorders, or protein misfolding diseases), include such diseases as Alzheimer's disease, Parkinson's disease, prion disease, type 2 diabetes, amyloidosis, and a wide range of other disorders .

1. Protein Structure & Disease
By :
196_Amani Mohe
197_Amal Ebrahim
198_Amal Elsayed
199_Amal Gamal
200_Amal Refaat
:Under supervision of
Prof.Dr. Mamdouh El_Sheshtawy

2.  protein, highly complex substance that is present in all living
organisms .
 They deserve the name protein , the Greek “proteios” = the
most important compound .
 Proteins are made up of hundreds or thousands of smaller
units called amino acids, which are attached to one another in
long chains.

3.  There are 20 different types of amino acids that can be
combined to make a protein .
 They are composed of :
1. amine (-NH2) group .
2. carboxylic acid (-COOH) group .
3. side chain ( R ) specific to each amino acid.

5. 4ry structure3ry structure2ry structure1ry structure
Polypeptide chains
, it may be :
1) homogenous .
2) heterogeneous .
Stabilized by :
non-covalent
bond .
Three dimensional
structure of
protein .
Stabilized by :
1) hydrogen bond .
2) disulfide bond .
3) Ionic bond .
4) Vander waals .
Types :
1) α-helixes .
2) β- pleated
sheets .
3) triple helixes .
:Stabilized by
hydrogen bond .
Linear sequence of
amino acids .
:Stabilized by
strong peptide
bond .
 Biochemists often refer to four distinct aspects of a
protein's structure .

6.  Protein folding is the process by which a protein structure
assumes its functional shape or conformation .
 Failure to fold into native structure generally produces
inactive proteins, but in some instances misfolded proteins
have modified or toxic functionality.

8.  proteopathy refers to a class of disease in which
certain proteins become structurally abnormal, and thereby
disrupt the function of cells, tissues and organs of the body.
 In this misfolded state, the proteins can become toxic in
some way or they can lose their normal function.
 They include such diseases as Alzheimer's
disease, Parkinson's disease , prion disease, type 2 diabetes
, amyloidosis , and a wide range of other disorders .

9. Amyloids
They are insoluble
fibrous protein
aggregates
sharing specific
structural traits.
Prion
Is a unique type
of infectious
agent, as it is
made only of
protein .
Chaperones
Proteins that have a
particularly complicated
or unstable
conformation sometimes
have difficulty achieving
their native state.

10. Accumulation of misfolded proteins can cause amyloid diseases . The
most prevalent one is Alzheimer's disease, Parkinson's disease and
Huntington's disease have similar amyloid origins. These diseases can
be sporadic or familial . The risk of getting any of these diseases
increases dramatically with age.

11.  Alzheimer's disease (AD) has been
identified as a protein misfolding disease
due to the accumulation of abnormally
folded amyloid beta protein in the brains of
Alzheimer's patients.
 AD is also considered a tauopathy due to
abnormal aggregation of the tau protein,
a microtubule-associated protein expressed
in neurons that normally acts to
stabilize microtubules in the
cell cytoskeleton.

12. Protein aggregation diseases are not exclusive to the central
nervous system; they can also appear in peripheral tissues.
Such diseases include type 2 diabetes, inherited chataracts,
some forms of atherosclerosis, hemodialysis-related disorders,
and short-chain amyloidosis, among many others.
 All these diseases have in common the expression of a
protein outside its normal context, leading to an irreversible
change into a sticky conformation rich in beta sheets that make
the protein molecules interact with each other.

13.  People with adult onset (type 2) diabetes
typically exhibit misfolded, insoluble protein
aggregates in their pancreas.
Regarding diabetes, these aggregates damage
the membrane (outer barrier) of certain
pancreatic cells, hindering the production of
insulin.
 There is evidence that an important step is
the action of intermediately misfolded and
aggregated proteins.
Such results suggest that the transition from an
intermediately aggregated protein to a more
extensively aggregated protein plays an
important role in the progression of type 2
diabetes.