the Department of Biochemical Sciences, National Chemical Laboratory, 411 008, Pune, India.
World J Microbiol Biotechnol. 1992 Jul;8(4):353-68. doi: 10.1007/BF01198746.
Xylans, the major portion of the hemicellulose of plant cell walls and grasses, are heteropolymers consisting principally of xylose and arabinose. Microbial xylanases with different multiplicities and properties are reported. Most studies on the mode of action of these xylanases have been carried out with fungi and there is very little information available on bacterial xylanases. Fungal xylanases have three or more substrate binding sites: for exampleAspergillus niger, Ceratocytis paradoxa, Cryptococcus albidus andChainia sp. endoxylanases have four to seven subsites with the catalytic site located at the centre of these sub-sites. The analysis of these sub-sites is either by kinetic or end-product analysis studies. Kinetic studies are used for exo-type enzymes while the end-product analysis studies are more convenient for endo-type enzymes. This review covers microbial xylanases with special emphasis on studies of sub-site mapping. The industrial applications of the microbial xylanases are also discussed.
木聚糖是植物细胞壁和草类的半纤维素的主要成分，是由木糖和阿拉伯糖组成的杂多糖。已经报道了具有不同多样性和特性的微生物木聚糖酶。这些木聚糖酶的作用模式的大多数研究都是在真菌中进行的，而关于细菌木聚糖酶的信息则非常有限。真菌木聚糖酶有三个或更多的底物结合位点：例如黑曲霉、多形拟内孢霉、白腐假丝酵母和链霉菌内切木聚糖酶有四到七个亚位点，催化位点位于这些亚位点的中心。这些亚位点的分析要么通过动力学或末端产物分析研究。动力学研究适用于外切型酶，而末端产物分析研究则更适用于内切型酶。这篇综述涵盖了微生物木聚糖酶，特别强调了亚位点映射的研究。还讨论了微生物木聚糖酶的工业应用。
