By: Dario Marotta 10/23/ ELASTASE A SERINE PROTEASE

1. Proteases = Protein  Trypsin  Chymotrypsin  Elastase 2. Pancreatic Lipase = Fat 3. Amylase = Carbohydrates 10/23/ ANATOMY

Composition  Hydrophobic Amino Acids  Glycine, Proline, Alanine, Valine Elastic Properties  Arteries  Lungs  Skin  Ligaments  Bladder 10/23/ ELASTIN

Step 1: Mechaelis Complex  Ser ~195 Hydroxyl Group = Nucleophile  Asp ~119 H-bond to His~57  His ~57 better (proton acceptor) Step 2: Tetrahedral Intermediate  His ~57 Accepts Ser ~195 Hydrogen Step 3: Deacylation  Water = nucleophile  Regenerates the catalytic triad 10/23/ REACTION MECHANISM

10/23/ SERINE PROTEASES Specificity Determines Function Serine Protease specificity is determined by size of binding pocket

DeLano, W.L The PyMOL Molecular Graphics System San Carlos, Ca, USA DeLano Scientific Valine ~190/~216  Isopropyl side chain restricts access  Alanine, Glycine, Valine 10/23/ SPECIFICITY Elastase Binding Pocket  Red = Catalytic Triad  Green = Valine ~190  Grey = Valine ~216

7 SPECIFICITY

8 ACTIVE SITE Catalytic triad Specificity residues block large side chains

9 ACTIVE SITE Tetrahedral intermediate - ready to leave and regenerate binding pocket residues

Generally not a membrane-bound enzyme, although membrane-bound forms do exist. 10 HYDROPATHY PLOT

10/23/ SEQUENCE ALIGNMENT FEBS Journal Volume 277, Issue 10, pages , 26 APR 2010 DOI: /j x Chymotrypsin-like Serine Proteases  hPR3 ( Human proteinase 3 )  hNE ( Human neutrophil elastase ) Signal peptides: Blue N-terminal peptides: Green C-terminal peptides: Orange Catalytic Triad: Green Stars Glycosylation Sites: Orange Stars A-Helices: Yellow B-Strands: Purple

10/23/ ADDITIONAL ORGANISMS

13 ELASTASE 3B SEQUENCE ALIGNMENT (VARIOUS SPECIES) Conserved Amino Acids His 57, Asp 102, Val 190, Ser 195

10/23/ HUMAN ELASTASE VARIATION

His 57, Asp 102, Val 190, Val 216 Ser HUMAN ELASTASE SEQUENCE ALIGNMENT Conserved Amino Acids

10/23/ STRUCTURE MAP FEBS Journal Volume 277, Issue 10, pages , 26 APR 2010 DOI: /j x Catalytic Triad: Green Glycosylation Sites: Orange A-Helices: Yellow B-Strands: Purple

Emphysema Cystic Fibrosis Inflammation Coronary Artery Disease Liver Disease Pancreatitis 10/23/ CLINICAL SIGNIFICANCE