摘要
用丙酮脱脂、稀酸处理、硫酸铵盐析和ＤＥＡＥ－５２纤维素柱层析等方法从大豆（Ｇ．ｍａｘ）中分离纯化得一种新类型胰蛋白酶抑制剂Ｔｉｘ．ＳＤＳ－ＰＡＧＥ分析显示Ｔｉｘ与已知的大豆蛋白酶抑制剂Ｔｉａ的相对分子质量均为２１０００，且Ｎ－末端均为ＡｓＰ；亲和电泳分析显示Ｔｉｘ与Ｔｉａ均可与胰蛋白酶完全结合；ＢＡＥＥ法测定显示出Ｔｉｘ对胰蛋白酶活性的抑制略小于Ｔｉａ；两者经ＣＮＢｒ裂解后电泳分析得到相同带型；纯化样品的氨基酸组成分析显示Ｔｉｘ比Ｔｉａ多了两个碱性氨基酸，因而Ｔｉｘ带有更多的正电荷．研究结果初步证明Ｔｉｘ是Ｋｕｎｉｔｚ类型中一种新的胰蛋白酶抑制剂．
ia and Tix were extracted from soybean seeds following the method modified by Mihoko Yamanoto, and purified by DEAE-52 column. Tix was the same relative molecular mass and N-terminal residue as Tia. Both inhibited trypsin activity at a ratio of 1: 1,but K, value of Tix was slightly higher than that of Tia. The results of PAGE and HPLC showed that the CNBr fragments of Tix were similar to those of Tia.In amino acid composition,there were two residues differences between Tix and Tia, with the result that Tix was more positively charged than Tia. Tix is a new electrophoretic variant of SBTi-A2 from soybean seed storage protein.
出处
《复旦学报（自然科学版）》
CSCD
北大核心
1996年第2期150-156,共7页
Journal of Fudan University：Natural Science
基金
国家自然科学基金
