Abstract
Several fractions demonstrating trypsin inhibitory activity were isolated from the seeds of the paprika plant (Capsicum annuum). One of the inhibitors, PSI-1.1, was purified to homogeneity and characterised. The mature form of PSI-1.1 has a molecular mass of 6053 Da and consists of 55 amino acids in a sequence showing over 80% identity with members of the inhibitors of potato-2 family. PSI-1.1 is a potent inhibitor of trypsin (Ki = 4.8 x 10(-10) M) and a somewhat weaker inhibitor of chymotrypsin (Ki = 4.7 x 10(-8) M) and pronase E (Ki = 5.9 x 10(-8) M). PSI-1.1 is resistant to heat up to 85 degrees C, to acidic conditions (down to pH 2.0) and to pepsin digestion, presumably due to its four disulfide bridges.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Amino Acid Sequence
-
Capsicum / chemistry*
-
Chromatography, High Pressure Liquid
-
Chromatography, Ion Exchange
-
Chymotrypsin / antagonists & inhibitors
-
Enzyme Stability
-
Evolution, Molecular
-
Hydrogen-Ion Concentration
-
Kinetics
-
Molecular Sequence Data
-
Peptide Fragments / chemistry
-
Plants, Medicinal*
-
Pronase / antagonists & inhibitors
-
Seeds / chemistry
-
Sequence Analysis
-
Sequence Homology, Amino Acid
-
Serine Proteinase Inhibitors / chemistry*
-
Serine Proteinase Inhibitors / isolation & purification
-
Serine Proteinase Inhibitors / pharmacology*
-
Temperature
-
Trypsin Inhibitors / chemistry
-
Trypsin Inhibitors / isolation & purification
-
Trypsin Inhibitors / pharmacology
Substances
-
Peptide Fragments
-
Serine Proteinase Inhibitors
-
Trypsin Inhibitors
-
Chymotrypsin
-
Pronase
Associated data
-
GENBANK/P01078
-
GENBANK/P01080
-
GENBANK/P05119
-
GENBANK/S24973
-
GENBANK/S43105
-
GENBANK/S43338
-
GENBANK/Z12753
-
GENBANK/Z29537