Biochem a1 Anti-Trypsin Flashcards
enzymes that cut peptide bonds
Proteases
Serine proteases have a serine residue as part of their
active site
catalytic triad
serine protease ex
Elastase
What released elastase ?
neutrophils
Action of elastase?
inflammation reactions
Elastase hydrolyses the peptide bond ——amino acids with————, such as——
after
aliphatic side chains
Ala, Gly or Val
How does elastase differ from trypsin
and chymotrypsin?
They are all serine proteases with different specificity in their cutting
Elastin primarily made up of these amino acids
Ala, Gly or Val
Chymotrypsin specificity in their cutting
Phenylalanine, Tryptophan, Tyrosine [aromatic]
Trypsin specificity in their cutting
Arginine, Lysine [positively charged]
Elastase specificity in their cutting
R = Alanine, Glycine, Valine [aliphatic
elastase (beneficial for—— immunity)
innate
What
are the major effects of elastase activity?
• Inflammatory reactions lead to release of
elastase
elastase Enzyme in the lung
destroys bacteria and
cellular debris
Without the inhibition of neutrophil elastase,
the enzyme destroys tissue surrounding the
alveoli à Emphysema
Excess elastase activity is controlled by the
protease inhibitor AAT (α 1
-antitrypsin
AAT protein is a
serpin’ (Serine Protease Inhibitor
AAT is produced in
liver
AAT protects the lungs from the
neutrophil elastase
Normal blood levels of AAT are
1.5 - 3.5 g/L.
reactive center of the AAT molecule, a
methionine amino acid side chain
AAT deficiency causes
Emphysema
M olecular basis of AAT deficiency:
- Genetic defects that prevent AAT synthesis
* Mutations that change AAT protein structure,
Mutations that change AAT protein structure,
Z AAT): Z AAT polymerizes
Alpha-1-Antitrypsin
deficiency leads to
Chronic Obstructive
Pulmonary Disease
( COPD)
