ISSN:
0749-503X
Keywords:
Secretion
;
methylotrophic yeast
;
glycosylation
;
methanol oxidase
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
The methylotrophic yeast Hansenula polymorpha, a host organism for the production of heterologous proteins, has been applied to produce the α-galactosidase from the plant Cyamopsis tetragonoloba (guar). The yeast/Escherichia coli shuttle expression vector used is based on the origin of replication of the endogenous 2 μm plasmid of Saccharomyces cerevisiae and the LEU2 gene of S. cerevisiae for selection in H. polymorpha. In the expression vector, the α-galactosidase is controlled by the methanol-regulated promoter from the methanol oxidase gene, MOX, of H. polymorpha. The signal sequence of SUC2 (invertase) from the yeast S. cerevisiae, was used to ensure secretion of the α-galactosidase enzyme. After transformation and stabilization, the expression vector was stably integrated in the genome. The active α-galactosidase enzyme was efficiently secreted (〉85%) and after methanol induction, the expression level was 42 mg/l. Amino-terminal sequencing of the purified α-galactosidase enzyme synthesized by H. polymorpha showed that the S. cerevisiae invertase signal sequence was correctly processed by H. polymorpha. The secreted α-galactosidase was glycosylated and had a sugar content of 9·5%. The specific activity of the α-galactosidase produced by H. polymorpha was 38 U mg-1 compared to 100 U mg-1 for guar α-galactosidase. Deglycosylation of the H. polymorpha α-galactosidase restored the specific activity completely.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/yea.320070505
Permalink
