African Journal of Biotechnology Vol. 2 (9), pp. 296-300, Semtember 2003

ISSN 1684-5315  © 2003 Academic Journals  

Full Length Research Paper

Enzyme activity of a Phanerochaete chrysosporium cellobiohydrolase (CBHI.1) expressed as a heterologous protein from Escherichia coli

Howard R.L.¹*, Masoko P.¹ and Abotsi E.²

¹Microbiology, School of Molecular and Life Sciences, University of the North, P/Bag X1106, Sovenga, 0727, South Africa 

²Biochemistry, School of Molecular and Life Sciences, University of the North, P/Bag X1106, Sovenga, 0727, South Africa.

Corresponding author: E-mail: howardr@unorth.ac.za, Tel/fax +27 15 2682862.

Accepted 11 August 2003

The aim of this study was to produce a secreted, heterologously expressed Phanerochaete chrysosporium cellobiohydrolase (CBHI.1) protein that required no in vitro chemical refolding and to investigate the cellulolytic activity of the clone expressing the glutathione S-transferase (GST) fused CBHI.1 protein.   Plate enzyme activity screening of E. coli cells transformed with pGEXcbhI.1 vector on carboxy-methyl-cellulose (CMC) produced several clones which produced clearing zones on CMC when induced.  A randomly selected representative pGEXcbhI.1 clone produced hydrolysis on both Avicel and CMC when induced.  Crude protein extracts obtained from the induced pGEXcbhI.1 clone exhibited time dependent enzymatic activity against both CMC and Avicel.        

Key words: Phanerochaete chrysosporium, cellobiohydrolase, cellulase activity, heterologous expression.