Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 2 9 2014 08 24 Purification and Characterization of Bowman-Birk Trypsin Inhibitor from Soybean 546 550 EN Chunmei Gu Xinxiu Song Linlin Zhao Shu Pan Guixin Qin Institute of Animal Science and Technology, Jilin Agricultural University, Changchun, China JFNR2014293 10.12691/jfnr-2-9-3 2014 08 10 2014 08 20 2014 08 24 In this paper, crude extract of a Bowman-Birk trypsin inhibitor from soybean meal was firstly isolated by a combination of , thermal denaturation, isoelectric precipitation and acetone precipitation. Then this extract was purified by DE-52 ion exchange and affinity chromatography. The results showed that soybean Bowman-Birk trypsin inhibitor (SBBI) was purified to 50.07-fold with trypsin activity of 822.31 U·mg-1. The purified SBBI gave a single protein band in SDS-PAGE electrophoresis. The accurate molecular mass of this inhibitor was determined to be 8837.46Da by MALDI-TOF. N-terminal sequence showed high homology with other serine proteinase inhibitors belonging to the Leguminosae family.