eng Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 2014-08-24 2 9 546 550 10.12691/jfnr-2-9-3 JFNR2014293 article Chunmei Gu 1 Xinxiu Song 1 Linlin Zhao 1 Shu Pan 1 Guixin Qin qgx@jlau.edu.cn 2 Institute of Food Science and Engineering, Jilin Agricultural University, Changchun, China Institute of Animal Science and Technology, Jilin Agricultural University, Changchun, China 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. http://pubs.sciepub.com/jfnr/2/9/3/jfnr-2-9-3.pdf soybean Bowman-Birk trypsin inhibitor purification characterization