In this paper , the advances in research of preparation of oligochitosan by acid degradation , oxidation degradation , enzyme degradation and composite degradation were discussed 介绍和评述了酸降解法、氧化降解法、酶降解法以及复合降解法等各种制备方法的研究进展。
Angiostatin ( as ) is a kind of polypeptide identified as a product of plasminogen cleavaged by protease . it blocks neovascularization by directly inhibiting endothelial cell proliferation and migration 血管抑素( angiostatin ， as )是血浆纤溶酶原( plasminogen ， plg )经蛋白水解酶降解生成的多肽片段，是直接作用于血管内皮细胞的血管生成抑制剂。
Chitosan was hydrolyzed by non - specific enzymes into chitooligosacchrides with some interesting functional properties and physiological activities , which have attracted many researchers in chitin science in recent years 摘要利用非专一性酶降解壳聚糖生成具有重要生理活性和功能性质的甲壳低聚糖，这已成为近年来甲壳素科学领域中的一个研究热点。
The restriction enzyme hind iii was used to cut the cucumber dna , and the fragment of the obtained dna is suitable to prepare the cucumber dna voltammetric biosensor . thus the sensor possessed excellent analytical characteristics 采用hind限制性内切酶降解所提黄瓜dna ，使之片断大小适合制备dna传感器，显著改善了dna传感器的重现性等性能。
In this paper , based on the introduction to physiological activity of oligochitosan , the advances in the preparation of oligochitosan by acid degradation , oxidation degradation , enzyme degradation and composite degradation were discussed 本文在介绍低聚壳聚糖的生理活性的基础上，重点评述了酸降解法、氧化降解法、酶降解法以及组合降解工艺等各种制备方法的研究进展。
Phaenerochaete chrysosporiun produces extracellular peroxidase system mainly consisting of lignin peroxidase and mn - dependent peroxidase , which has peticuliar mechanism of enzyme for degradation of many organic pollutants 摘要黄孢原毛平革菌由于其所产胞外过氧化物酶系（主要由木素过氧化物酶和锰过氧化物酶组成）的独特酶降解机理，能降解多种有机污染物，在环境工程中有着巨大的应用前景。
Fusion protein expression system can overcome those problem , increased the yield of yield of recombinant protein in e . coli . this remarkable increase in protein yield was thought to be due to protection of the target protein from proteolysis , improved folding , and efficient mrna translation . fusion protein also make the detection and purification easy , is a good strategies for achieving high - level expression of genes in escherichia coli 小分子量异源蛋自在人肠杆菌的表达受mrna不稳定、翻译起始效率低、易被蛋自酶降解等因素的干扰，较难获得高效表达，通过与已高表达的蛋自融合表达可以克服以上问题，可以使大多数蛋白获得高效表达。
