African Journal of Biotechnology Vol. 4 (10), pp. 1185-1188, October 2005          
ISSN 1684–5315 © 2005 Academic Journals

Full Length Research Paper

Refolding and characterisation of a heterologous expressed Phanerochaete chrysosporium cellobiohydrolase (CBHI.2)

Howard RL

Microbiology, School of Molecular and Life Sciences, University of Limpopo, P/Bag X1106, Sovenga, 0727, South Africa. E-mail: howardr@ul.ac.za. Tel/fax: +27 15 268 2862.

Accepted 27 September, 2005

Cloned Phanerochaete chrysosporium ME446 cbhI.2 cDNA was successfully expressed in Escherichia coli as an insoluble, internal, biologically inactive protein. In vitro chemical refolding restored the activity of the crude CBHI.2. However, this enzyme was active against 4-methylumbelliferyl-ß-D-cellobioside (MUC) and 4-methyllumbelliferyl-ß-D-lactopyranoside (MUL) substrates only.  The crude enzyme lost almost 50% of its activity at 5 min at 100^oC heat treatment whereas total inactivation was achieved at 30 min.     

Key words: Phanerochaete chrysosporium, CBHI.2, chemical refolding, heat-inactivation.