Crystallization, data collection and phasing of black-eyed pea trypsin/chymotrypsin inhibitor in complex with bovine β-trypsin

• Published in: Acta crystallographica. Section D, Biological crystallography. Biological crystallography., 2003-10, Vol.59 (10), p.1828-1830
• Main Authors: Barbosa, J. A. R. G., Teles, R. C. L., Forrer, V. P., Guimarães, B. G., Medrano, F. J., Ventura, M. M., Freitas, S. M.
• Format: Article
• Language: English
• Subjects: Animals; Cattle; Crystallization - methods; Crystallography, X-Ray - methods; Data Collection; Pisum sativum - chemistry; Plant Proteins - chemistry; Protein Conformation; Seeds - chemistry; trypsin; Trypsin - chemistry; trypsin/chymotrypsin inhibitor
• ISSN: 1399-0047; 0907-4449; 1399-0047
• DOI: 10.1107/S090744490301641X

The black‐eyed pea trypsin and chymotrypsin inhibitor (BTCI) is a Bowman–Birk‐type inhibitor from Vigna unguiculata seeds. A complex of BTCI with bovine β‐trypsin was crystallized by the hanging‐drop vapour‐diffusion method with ammonium sulfate as precipitant. Crystals belong to the orthorhombic space group P212121, with unit‐cell parameters a = 59.3, b = 61.8, c = 80.0 Å. Diffraction data were collected to 2.36 Å resolution and were processed to give an overall Rsym of 0.137. The Matthews coefficient for one complex per asymmetric unit is 2.2 Å3 Da−1, with a corresponding solvent content of 43%. After molecular replacement and initial refinement, the model gives an Rcryst of 0.361 and an Rfree of 0.432.