The primary role of the P1 residue (ser359) of alpha-1-proteinase inhibitor.
The replacement of ser359 with ala359 at the P1 position in human alpha-1-proteinase inhibitor results in the production of a variant protein containing 15% of the inhibitory activity of the normal inhibitor. Separation of active from inactive inhibitor on anhydrochymotrypsin-sepharose yields a form which has a second order association rate with neutrophil elastase which is approximately one half that for the native protein. These data indicate that the P1 residue is not of primary importance during the interaction of proteinases with alpha-1-proteinase inhibitor. Since substitution of alanine for serine causes the formation, primarily, of inactive inhibitor the major function of ser359 probably involves proper folding to give a functionally active inhibitory conformation.
Matheson
N
N
Dept. of Biochemistry, University of Georgia, Athens 30602.
Bathurst
I
I
Travis
J
J
D000409:Alanine; D000595:Amino Acid Sequence; D001665:Binding Sites; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism*; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009154:Mutation; D009504:Neutrophils / Q000201:enzymology; D010196:Pancreatic Elastase / Q000378:metabolism; D010446:Peptide Fragments; D010447:Peptide Hydrolases / Q000378:metabolism; D011487:Protein Conformation; D012694:Serine; D012697:Serine Endopeptidases / Q000378:metabolism; D013329:Structure-Activity Relationship; D000515:alpha 1-Antitrypsin
D001798:Blood Proteins; D010446:Peptide Fragments; D000515:alpha 1-Antitrypsin; D012694:Serine; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D010196:Pancreatic Elastase; D000409:Alanine