Biomaterial Database

Characterization of a proteinase inhibitor isolated from the fungal pathogen Coccidioides immitis. 1989

L Yuan, and G T Cole

Department of Botany, University of Texas, Austin 78713-7640.

A proteinase inhibitor was isolated from the cytosol and cell wall of the fungal respiratory pathogen Coccidioides immitis. The inhibitor was purified to apparent homogeneity by acid precipitation, gel filtration and reverse-phase h.p.l.c. It has an Mr of about 5000 under reducing conditions, as revealed by SDS/polyacrylamide-gel electrophoresis, and is both heat-stable and tolerant to low pH. The inhibitor can efficiently block activity of a 36,000-Mr serine proteinase previously isolated from the same cell-wall fraction of C. immitis, and the two molecules react in a 1:1 stoichiometry. The dissociation constant (Ki) of the enzyme-inhibitor complex is 2.3 x 10(-8) M. We suggest that the low-Mr inhibitor may play a role in regulation of the activity of the cell-wall-associated 36,000-Mr proteinase during sporulation of C. immitis.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011480	Protease Inhibitors	Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).	Antiprotease,Endopeptidase Inhibitor,Endopeptidase Inhibitors,Peptidase Inhibitor,Peptidase Inhibitors,Peptide Hydrolase Inhibitor,Peptide Hydrolase Inhibitors,Peptide Peptidohydrolase Inhibitor,Peptide Peptidohydrolase Inhibitors,Protease Antagonist,Protease Antagonists,Antiproteases,Protease Inhibitor,Antagonist, Protease,Antagonists, Protease,Hydrolase Inhibitor, Peptide,Hydrolase Inhibitors, Peptide,Inhibitor, Endopeptidase,Inhibitor, Peptidase,Inhibitor, Peptide Hydrolase,Inhibitor, Peptide Peptidohydrolase,Inhibitor, Protease,Inhibitors, Endopeptidase,Inhibitors, Peptidase,Inhibitors, Peptide Hydrolase,Inhibitors, Peptide Peptidohydrolase,Inhibitors, Protease,Peptidohydrolase Inhibitor, Peptide,Peptidohydrolase Inhibitors, Peptide
D002473	Cell Wall	The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.	Cell Walls,Wall, Cell,Walls, Cell
D003045	Coccidioides	A mitosporic fungal genus which causes COCCIDIOIDOMYCOSIS.	Coccidioides immitis
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D000803	Angiotensin I	A decapeptide that is cleaved from precursor angiotensinogen by RENIN. Angiotensin I has limited biological activity. It is converted to angiotensin II, a potent vasoconstrictor, after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME.
D012697	Serine Endopeptidases	Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.	Serine Endopeptidase,Endopeptidase, Serine,Endopeptidases, Serine
D015842	Serine Proteinase Inhibitors	Exogenous or endogenous compounds which inhibit SERINE ENDOPEPTIDASES.	Serine Endopeptidase Inhibitor,Serine Endopeptidase Inhibitors,Serine Protease Inhibitor,Serine Protease Inhibitors,Serine Proteinase Antagonist,Serine Proteinase Antagonists,Serine Proteinase Inhibitor,Serine Proteinase Inhibitors, Endogenous,Serine Proteinase Inhibitors, Exogenous,Serine Protease Inhibitors, Endogenous,Serine Protease Inhibitors, Exogenous,Antagonist, Serine Proteinase,Endopeptidase Inhibitor, Serine,Inhibitor, Serine Endopeptidase,Inhibitor, Serine Protease,Inhibitor, Serine Proteinase,Protease Inhibitor, Serine,Proteinase Antagonist, Serine,Proteinase Inhibitor, Serine