The Complete Amino Acid Sequence of a Trypsin Inhibitor from Bauhinia variegata var. candida Seeds

Abstract

Trypsin inhibitors of two varieties of Bauhinia variegata seeds have been isolated and characterized. Bauhinia variegata candida trypsin inhibitor (BvcTI) and B. variegata lilac trypsin inhibitor (BvlTI) are proteins with Mr of about 20,000 without free sulfhydryl groups. Amino acid analysis shows a high content of aspartic acid, glutamic acid, serine, and glycine, and a low content of histidine, tyrosine, methionine, and lysine in both inhibitors. Isoelectric focusing for both varieties detected three isoforms (pI 4.85, 5.00, and 5.15), which were resolved by HPLC procedure. The trypsin inhibitors show Ki values of 6.9 and 1.2 nM for BvcTI and BvlTI, respectively. The N-terminal sequences of the three trypsin inhibitor isoforms from both varieties of Bauhinia variegata and the complete amino acid sequence of B. variegata var. candida L. trypsin inhibitor isoform 3 (BvcTI-3) are presented. The sequences have been determined by automated Edman degradation of the reduced and carboxymethylated proteins of the peptides resulting from Staphylococcus aureus protease and trypsin digestion. BvcTI-3 is composed of 167 residues and has a calculated molecular mass of 18,529. Homology studies with other trypsin inhibitors show that BvcTI-3 belongs to the Kunitz family. The putative active site encompasses Arg (63)-Ile (64).

Characterization and Pharmacological Properties of a Novel Multifunctional Kunitz Inhibitor from Erythrina velutina Seeds

“…The molecular weights obtained for the trypsin inhibitor purified from E. velutina are in agreement with those determined for the Kunitz family of inhibitors with molecular mass ranging from 18 to 26 kDa, such as ECTI ( Enterolobium contortisiliquum seeds trypsin inhibitor), BvcTI ( Bauhinia variegata trypsin inhibitor), DMTI ( Dimorphandra mollis seeds trypsin inhibitor) AETI ( Archidendron ellipticum seeds trypsin inhibitor), CBTI-2 ( Caesalpinia bonduc seeds trypsin inhibitor) and ILTI ( Inga laurina seeds trypsin inhibitor) [19], [56]–[60]. It is important to point out that the mass spectrometry analyses show the possible existence of other inhibitor isoforms since small tags of other sequences not presented here were found.…”

Identification of a Kunitz-Type Proteinase Inhibitor from Pithecellobium dumosum Seeds with Insecticidal Properties and Double Activity

“…In this study, a related Kunitz inhibitor from P. domusum seeds was purified and characterized and its effects on digestive proteinsases from insect pests were examined in vitro. The PdKI purified is a protein with a unique polypeptide chain of molecular mass of 19.7 kDa, in agreement with the molecular mass of other trypsin inhibitors ( − ). Thermal inactivation of PdKI at different temperatures resulted in a progressive loss of trypsin-inhibiting activity at temperatures >40 °C and an ∼40% decrease at 100 °C.…”

Phytochemical Studies on Bauhinia racemosa Lam. Bauhinia purpurea Linn. and Hardwickia binata Roxb

“…Mukherjee and Laloraya (1977) have studied on the ketoacids and free amino acid pattern during leaf growth in Bauhinia purpurea 2 . Diciero et al, (1998) have analyzed the seed of B. variegata and its amino acid analysis showed high content of asparatic acid, glutamic acid, serine and glycine 3 . Rehman and Begum (1966) isolated 3-galactoside and 3-rhamnoside of kaemferol from the leaves of B. variegata 4 .…”