Specificity of acyl-CoA binding protein to acyl-CoAs: influence on the lipid metabolism in Aspergillus oryzae

Abstract

Acyl-CoA binding protein (ACBP) is involved in lipid metabolism and regulation of gene expression in eukaryotic cells, however, the specific functional roles of this important class of proteins remain to be elucidated. We have cloned and expressed a recombinant Aspergillus oryzae ACBP (AoACBP) that has a preference for binding relatively long chain acyl-CoAs such as palmitoyl (C16:0)-CoA (K_d = 82 nM) and stearoyl (C18:0)-CoA (K_d = 59 nM) by microscale thermophoresis binding assay. The high affinities for binding C16:0-CoA and C18:0-CoA were also conformed to the composition of fatty acids in A. oryzae 3.042. Moreover, the increased AoACBP levels were analyzed by Western blot procedure. And the expression levels and distribution patterns of AoACBP in this fungal life cycle were also investigated by RT-PCR and immunofluorescence. The accumulation of AoACBP have an effect on lipid metabolism, and it was significantly increased from 24 to 48 h suggest that AoACBP plays an important role in the later growth stage of A. oryzae 3.042 for fatty acid synthesis.