A truncated glucoamylase gene fusion for heterologous protein secretion from Aspergillus niger |
| |
Authors: | David J. Jeenes Beate Marczinke Donald A. MacKenzie David B. Archer |
| |
Affiliation: | A.F.R.C. Institute of Food Research, Norwich Research Park, Colney, Norwich, UK |
| |
Abstract: | Abstract The secreted yield of hen egg-white lysozyme (HEWL) from the filamentous fungus Aspergillus niger was increased 10–20-fold by constructing a novel gene fusion. The cDNA sequence encoding mature HEWL was fused in frame to part of the native A. niger gene encoding glucoamylase ( gla A), separated by a proteolytic cleavage site for in vivo processing. Using this construct, peak secreted HEWL yields of 1 g/l were obtained in A. niger shake flask cultures compared to about 50 mg/l when using an expression cassette lacking any gla A coding sequence. The portion of gla A used in the gene fusion encoded the first 498 amino acids of glucoamylase (G498) and comprised its secretion signal, the catalytic domain and most of the O-glycosylated linker region which, in the entire glucoamylase molecule, spatially separates and links the catalytic and starch-binding domains. |
| |
Keywords: | Gene fusion Aspergillus niger Filamentous fungus Protein secretion Heterologous protein Lysozyme |
|
|