ISOLATION AND CERTAIN PROPERTIES OF A THERMOSTABLE ENDOGLUCANASE FROM ESCHERICHIA-COLI C 600 (PKNE-102), ENCODED BY A GENE FROM CLOSTRIDIUM-THERMOCELLUM

An endoglucanase encoded by a gene from C. thermocellum not previously described by isolated from a recombinant stair, of E. coli (pKNE-102). The purification procedure includes a step of precipitation with ammonium sulfate, thermoprecipitation of inert proteins, chromatography on the polyvinyl carrier Toyopearl HW-50F, and chromatofocusing on a Mono P HR 5/20 high-performance column. According to the results of denaturing electrophoresis in the presence of SDS, the preparation of endoglucanase, after chromatography on Toyopearl, contains two components - major and minor - with close molecular weights: approximately 41 and 42 kD, respectively. These proteins also differ in isoelectric points (pI 4.45 and 4.4, respectively) and can be separated by chromatofocusing. Both components are active and have similar enzymatic properties; their distinguishing feature is a very high thermolability.