Protease from the sarcocarp of Trichosanthes bracteata.
A protease has been purified from sarcocarp of Trichosanthes bracteata (Lam.) Voigt by four steps of chromatography. Its M(r) was estimated by SDS-PAGE to be ca 67,000. The optimum pH of the enzyme was 11 at 35 degrees using casein substrate. The enzyme was strongly inhibited by di-isopropyl fluorophosphate, but not by EDTA and cysteine protease inhibitors. The oxidized insulin B-chain was cleaved at the peptide bonds of Cys7 (SO3H)-Gly8, Glu13-Ala14, Try16-Leu17 by the enzyme for 1 min. The results indicated that the T. bracteata protease is serine protease, similar to cucumisin from the sarcocarp of melon fruit (Cucumis melo L. var. Prince).
Kaneda
M
M
Department of Chemistry, Faculty of Science, Kagoshima University, Japan.
Uchikoba
T
T
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D007328:Insulin / Q000378:metabolism; D008969:Molecular Sequence Data; D010944:Plants / Q000201:enzymology*; D012697:Serine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013379:Substrate Specificity
D007328:Insulin; D015842:Serine Proteinase Inhibitors; D012697:Serine Endopeptidases