摘要
用粘度测定法和还原糖测定法，研究了中性蛋白酶非专一性降解壳聚糖过程中温度、ｐＨ 值、反应时间、酶浓度、底物浓度、金属离子及壳聚糖的脱乙酰度对中性蛋白酶降解壳聚糖反应速度的影响，确定了以壳聚糖为底物的中性蛋白酶的一些催化特性：最适温度为５０ ℃；最适ｐＨ 值为６ ．０ ；米氏常数 Ｋｍ 值为１ ．１ ×１０ － ２ ｇ／ ｍＬ；一定浓度的Ｃｕ２ ＋ 、Ｂａ２ ＋ 、Ｍｎ２ ＋ 抑制该酶的活性；ＩＣＨ２ ＣＯＯＨ 是激活剂。随着壳聚糖脱乙酰度的提高，降解速度降低。
The effects of reaction temperature, pH, substrate and enzyme concentration, some metal ions and the deacetylation degree of chitosan on the hydrolytic velocity of chitosan by neutral proteinase were investigated. The M η was decreased quickly at the catalysis of neutral proteinase. The optimum temperature and optimum pH were 50 ℃ and 6.0 respectively, and the K m value was 1.1×10 -2 g/mL. Such ions as Ba 2+ ,Mn 2+ and Cu 2+ were inhibitors, while ICH 2COOH can activated the activity of neutral proteinase. The reaction velocity was reduced while the deacetylation degree of chitosan raised.
出处
《功能高分子学报》
CAS
CSCD
1999年第3期293-296,共4页
Journal of Functional Polymers
基金
江苏省科委"九五"重点攻关项目和省教委基金
