Biomaterial Database

Natural plant enzyme inhibitors. V. A trypsin/chymotrypsin inhibitor from Alocasia macrorhiza tuber. 1977

S Sumathi, and T N Pattabiraman

A trypsin/chymotrypsin inhibitor was isolated from the tubers of Alocasia macrorhiza by extraction at pH 7.6, heat treatment at 80 degrees C, ammonium sulphate precipitation and successive column chromatography on CM-cellulose, DEAE-Sephadex A-50 and Sephadex G-100. The inhibitor was pure by cellulose acetate electrophoresis. The molecular weight was approximately 32 000 as determined by gel filtration on Sephadex G-100. The inhibitor acted on bovine trypsin, human trypsin and bovine chymotrypsin. It had no action on human chymotrypsin, subtilisin BPN', pronase, Aspergillus oryzae protease, human and porcine pepsins. The binding sites for bovine trypsin and chymotrypsin are not mutually exclusive. The inhibitor was stable over a pH range of 1--10. The purified inhibitor was far more thermostable than the crude inhibitor. The purified inhibitor lost only 33% of activity on heat treatment at 95 degrees C for 2 h. Trinitrobenzene sulphonate treatment resulted in the loss of antichymotryptic activity faster than the antitrypsin activity of the inhibitor.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002918	Chymotrypsin	A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.	Alpha-Chymotrypsin Choay,Alphacutanée,Avazyme
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D014302	Trinitrobenzenesulfonic Acid	A reagent that is used to neutralize peptide terminal amino groups.	Picrylsulfonic Acid,Trinitrobenzene Sulfonate,2,4,6-Trinitrobenzene Sulfonate,Trinitrobenzenesulfonic Acid, Sodium Salt,Sulfonate, Trinitrobenzene
D014361	Trypsin Inhibitors	Serine proteinase inhibitors which inhibit trypsin. They may be endogenous or exogenous compounds.	Trypsin Inhibitor,Inhibitor, Trypsin,Inhibitors, Trypsin