Purification of a trypsin inhibitor (PFTI) from pumpkin fruit phloem exudate and isolation of putative trypsin and chymotrypsin inhibitor cDNA clones.
Biol Chem Hoppe Seyler
; 376(5): 281-7, 1995 May.
Article
in En
| MEDLINE
| ID: mdl-7662170
ABSTRACT
The major trypsin inhibitor from pumpkin (Cucurbita maxima cv Supermarket Hybrid) fruit phloem exudate was purified by affinity and reverse phase chromatography. The protein has a molecular weight of approximately 8100 by SDS-PAGE and is blocked at the N-terminal serine. Following sequencing of a CNBr fragment, 3'- and 5'-RACE were used to isolate full length cDNAs corresponding to a trypsin inhibitor and to two chymotrypsin inhibitors. The three genes are similar, both in their translated and non-translated regions. Comparison of the full length translated proteins show that they are members of the proteinase inhibitor I family and almost identical apart from the P1 site in the proteinase binding loop. The genes encode proteins of 67 amino acids and appear to lack not only both pre- and prepro-peptide sequences but also the single disulphide present in most proteinase inhibitor I family members.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plants
/
Chymotrypsin
/
Trypsin Inhibitors
/
DNA, Plant
/
Exudates and Transudates
Language:
En
Journal:
Biol Chem Hoppe Seyler
Journal subject:
BIOQUIMICA
Year:
1995
Document type:
Article