A Novel Trypsin and -Chymotrypsin Inhibitor from Maclura pomifera Seeds

LAZZA CM; TREJO SA; OBREGÓN WD; PISTACCIO LG; CAFFINI NO; LÓPEZ LMI

LETTERS IN DRUG DESIGN & DISCOVERY

BENTHAM SCIENCE PUBL LTD

Lugar: Oak Park; Año: 2010 vol. 7 p. 244 - 249

1570-1808

A new peptidic protease inhibitor (MpI) has been isolated from Maclura pomifera seeds, being the first trypsin and chymotrypsin inhibitor from a species belonging to the family Moraceae. MpI was purified by acetone precipitation, gel filtration and ion exchange chromatography, successively, with purification factors of 112 and 109 for the aforemen- tioned enzymes, which are infrequent high values for inhibitors isolated from seeds. MpI showed a unique band in SDS- Tricine PAGE (Mr 11 kDa) and isoelectric focusing (pI = 5.2), inhibited the serine proteases trypsin and alpha-chymotrypsin (IC50 0.17 and 0.7 μg/ml, respectively), but not cathepsin B (cysteine protease), cathepsin D (aspartic protease) nor car- boxypeptidase A (metallo protease). The N-terminal sequence was determined (AREPKFSTHCEEEESR) but no homol- ogy was detected with other peptide inhibitors isolated from seeds. Preliminary assays related to blood clotting reactions showed that the isolated inhibitor significatively increased the activated partial thromboplastin time (APTT), suggesting its potential use in the treatment of blood coagulation disorders.