title: A trypsin-chymotrypsin inhibitor with antiproliferative activity from small glossy black soybeans.
abstract: A trypsin inhibitor with a molecular mass of about 19 kDa was isolated from seeds of Chinese black soybean Glycine max cv. "Small Glossy Black". It was isolated using a protocol that comprised ion exchange chromatography on Q-Sepharose, SP-Sepharose and DEAE-cellulose. It was adsorbed on all three ion exchangers. It inhibited trypsin with an IC(50) of 19 microM and chymotrypsin with an IC(50) of 14.3 microM. Its trypsin inhibitory activity was stable in the pH range pH 3-pH 13 and in the temperature range 0 degree C-60 degrees C. The trypsin inhibitor was inhibited by dithiothreitol (from 5 to 25 mM) in a dose-dependent manner. It exhibited an N-terminal sequence highly homologous to Kunitz-type trypsin inhibitors. It inhibited HIV-1 reverse transcriptase with an IC(50) of 0.16 microM, and suppressed proliferation of MCF-7 breast cancer cells with an IC(50) of 4.3 microM and HepG2 hepatoma cells with an IC(50) higher than 25 microM. The trypsin inhibitor lacked antifungal activity and mitogenic activity towards mouse splenocytes.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Ye
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin / Q000037:antagonists & inhibitors*; D004229:Dithiothreitol; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012639:Seeds; D013025:Glycine max / Q000737:chemistry*; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D018894:Reverse Transcriptase Inhibitors; D014361:Trypsin Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase; D002918:Chymotrypsin; D004229:Dithiothreitol