ISOLATION AND IDENTIFICATION OF TWO NOVEL SDS-RESISTANT SECRETED CHITINASES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们从台湾南部土壤中分离到两种耐十二烷基硫酸钠的内切几丁质酶，分别命名为ASCHI53和ASCHI61。MALDI-TOF质量测定表明，ASCHI53和ASCHI61的相对分子质量分别为53,527和61,202 Da。对这两种几丁质酶的N端序列分析表明，这两种几丁质酶是新的蛋白质。甲壳素与这两种内切几丁质酶反应生成六聚体甲壳素低聚糖，这是一种已知具有多种强大生物医学功能的化合物。在5%的十二烷基硫酸钠存在下，ASCHI53和ASCHI61分别保持了65%和75%的几丁质酶活性，而在10%的β-巯基乙醇存在下，ASCHI53和ASCHI61的几丁质酶活性完全保持。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have isolated two SDS-resistant endochitinases, designated as ASCHI53 and ASCHI61, from Aeromonas schubertii in the soil of southern Taiwan. Mass measurement with MALDI-TOF indicates that the molecular weights are 53,527 Da for ASCHI53 and 61,202 Da for ASCHI61. N-terminal sequencing of these two chitinases suggests that thye are novel proteins. Degredation of chitin with these two endochitinases gives rise to hexameric chitin oligosaccharide, a compound known to have various potent biomedical functions. In the presence of 5% SDS, ASCHI53 and ASCHI61 retain 65% and 75% chitinase activities, respectively while the chitinolytic activities completely retain even in the presence of 10% beta-mercaptoethanol.