Purification, inhibitory properties and amino acid sequence of a new serine proteinase inhibitor from white mustard (Sinapis alba L.) seed.
A new serine proteinase inhibitor, mustard trypsin inhibitor 2 (MTI-2), has been isolated from white mustard (Sinapis alba L.) seed by affinity chromatography and reverse phase HPLC. The protein inhibits the catalytic activity of bovine beta-trypsin and bovine alpha-chymotrypsin, with dissociation constants (Kd) of 1.6 x 10(-10) M and 5.0 x 10(-7) M, respectively, at pH 8.0 and 21 degrees C, the stoichiometry of both proteinase-inhibitor complexes being 1:1. The amino acid sequence of MTI-2, which was determined following S-pyridylethylation, is comprised of 63 residues, corresponding to a molecular weight of about 7 kDa, and shows only extremely limited homology to other serine proteinase inhibitors.
Menegatti
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E
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Italy.
Tedeschi
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G
Ronchi
S
S
Bortolotti
F
F
Ascenzi
P
P
Thomas
R M
RM
Bolognesi
M
M
Palmieri
S
S
D000595:Amino Acid Sequence; D002918:Chymotrypsin / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008969:Molecular Sequence Data; D009149:Mustard Plant / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010946:Plants, Medicinal; D012639:Seeds / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000235:genetics* / Q000302:isolation & purification* / Q000494:pharmacology*; D014357:Trypsin / Q000187:drug effects
D010446:Peptide Fragments; D015842:Serine Proteinase Inhibitors; D002918:Chymotrypsin; D014357:Trypsin