CRYSTAL STRUCTURE OF AN ACTIVE FORM OF PORCIN TRYPSIN. A. Johnson, Vasantha Pattabhi and P.V.Sundaram⁺ Department of Biophysics, University of Madras, Guindy Campus, Madras-600025, INDIA, ⁺Protein Engineering and Biomedical Research Voluntary Health Services Campus, Madras-6000113, INDIA

An active form of porcine trypsin has been crystallised from acetate buffer at pH 6.7 using 0.4M ammonium sulfate as a precipitant at 20 C. The crystals belong to P21 21 21 space group with cell dimensions a=47.07, b=53.82, c=77.7A. Three dimensional data has been collected up to 1.8 Å resolution. The structure solution is by molecular replacement.Conformational comparisons of the active site residues with those of the inactive form of porcine trypsin will be presented.