Isolation of a trypsin inhibitor with deletion of N-terminal pentapeptide from the seeds of Momordica cochinchinensis, the Chinese drug mubiezhi.
A trypsin inhibitor, MCCTI-1, with a molecular weight of 3479 Da as determined by mass spectrometry, was isolated from Momordica cochinchinensis seeds with a procedure involving extraction with 5% acetic acid, ammonium sulfate precipitation, ion exchange chromatography on CM-Sepharose and reverse-phase high performance liquid chromatography. The sequence of its first 13 N-terminal amino acid residues was ILKKCRRDSDCPG which was about 85% identical with the sequence of trypsin inhibitor MCTI-1 from Momordica charantia Linn. When compared with the sequences of most other squash family trypsin inhibitors, the sequence of MCCTI-1 was characterized by the deletion of a pentapeptide from the N-terminus. Trypsin inhibitors also existed in seeds of some hitherto uninvestigated Cucurbitaceae species.
Department of Biochemistry, Chinese University of Hong Kong, Shatin.
B
B
Huang
T B
TB
Ng
W P
WP
Fong
C C
CC
Wan
H W
HW
Yeung
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D019662:Cucurbitaceae / Q000737:chemistry; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D029775:Momordica; D010446:Peptide Fragments / Q000737:chemistry; D010940:Plant Proteins; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000494:pharmacology
D004365:Drugs, Chinese Herbal; D010446:Peptide Fragments; D010940:Plant Proteins; D014361:Trypsin Inhibitors