Purification of Clostridium thermocellum xylanase Z expressed in Escherichia coli and identification of the corresponding product in the culture medium of C. thermocellum.

摘要: An endoxylanase encoded by the xynZ gene of Clostridium thermocellum was purified from Escherichia coli harbouring a fragment cloned in pUC8. The enzyme showed two active bands Mr 41,000 and 39,000, latter one presumably derived former through proteolysis. highly on xylan para-nitrophenyl-beta-D-xylobioside. major end product hydrolysis xylobiose. With an antiserum raised against E. coli, immunoreactive polypeptide 90,000, corresponding to entire product, detected culture supernatant C. grown cellulose. By immunological detection, xylanase Z shown be associated with cellulose-binding, high-molecular-weight fraction whose properties coincided those described previously for cellulose-degrading complex known as cellulosome. Images