title: Primary structure and specificity of a serine proteinase inhibitor from paprika (Capsicum annuum) seeds.
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.
authors.affiliation: Institute of Organic Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria.
authors.forename: N
authors.initials: N
authors.lastname: Antcheva
authors.forename: A
authors.initials: A
authors.lastname: Patthy
authors.forename: A
authors.initials: A
authors.lastname: Athanasiadis
authors.forename: B
authors.initials: B
authors.lastname: Tchorbanov
authors.forename: S
authors.initials: S
authors.lastname: Zakhariev
authors.forename: S
authors.initials: S
authors.lastname: Pongor
mesh_terms: D000595:Amino Acid Sequence; D002212:Capsicum / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D004795:Enzyme Stability; D019143:Evolution, Molecular; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010946:Plants, Medicinal; D011402:Pronase / Q000037:antagonists & inhibitors; D012639:Seeds / Q000737:chemistry; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D013696:Temperature; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; D002918:Chymotrypsin; D011402:Pronase