Novel Hydrophobic Surface Binding Protein, HsbA, Produced by Aspergillus oryzae

Abstract

Hydrophobic surface binding protein A (HsbA) is a secreted protein (14.5 kDa) isolated from the culture broth of Aspergillus oryzae RIB40 grown in a medium containing polybutylene succinate-co-adipate (PBSA) as a sole carbon source. We purified HsbA from the culture broth and determined its N-terminal amino acid sequence. We found a DNA sequence encoding a protein whose N terminus matched that of purified HsbA in the A. ozyzae genomic sequence. We cloned the hsbA genomic DNA and cDNA from A. oryzae and constructed a recombinant A. oryzae strain highly expressing hsbA. Orthologues of HsbA were present in animal pathogenic and entomopathogenic fungi. Heterologously synthesized HsbA was purified and biochemically characterized. Although the HsbA amino acid sequence suggests that HsbA may be hydrophilic, HsbA adsorbed to hydrophobic PBSA surfaces in the presence of NaCl or CaCl 2 . When HsbA was adsorbed on the hydrophobic PBSA surfaces, it promoted PBSA degradation via the CutL1 polyesterase. CutL1 interacts directly with HsbA attached to the hydrophobic QCM electrode surface. These results suggest that when HsbA is adsorbed onto the PBSA surface, it recruits CutL1, and that when CutL1 is accumulated on the PBSA surface, it stimulates PBSA degradation. We previously reported that when the A. oryzae hydrophobin RolA is bound to PBSA surfaces, it too specifically recruits CutL1. Since HsbA is not a hydrophobin, A. oryzae may use several types of proteins to recruit lytic enzymes to the surface of hydrophobic solid materials and promote their degradation.

Bioactive Properties of Japanese Fermented Fish Paste, Fish Miso, Using Koji Inoculated With Aspergillusoryzae

“…Interestingly, some peptide subunits, particularly those of approximately 36.5 kDa and 31.1 kDa, developed during the early stages of fermentation and became prominent over 30 days of fermentation. These protein subunits were probably resulted from the synthesis of protein by the starter A. oryzae (koji) mold, and this suggestion is strongly supported by the results of Ohtakiet al [39] and Rashid et al [40]. …”

Genome expansion and lineage-specific genetic innovations in the forest pathogenic fungi Armillaria

“…In addition, three cell wall galactomannoproteins show high expression in NATuRE ECOlOgy & EvOluTiON fruiting bodies (up to logFC VM = 13.5, Supplementary Table 12), two of which were expressed only in caps, whereas ARMOST_19505 was highly expressed throughout development. These genes are homologous to the Aspergillus hydrophobic cell-surface protein HsbA, which has been hypothesized to recruit hydrolytic enzymes during lignocellulose degradation 34 and appressorium attachment to host surfaces 35 . As lignocellulose-related processes are inactive in fruiting bodies, their expression suggests specific roles during cap development, possibly in cell-wall remodelling.…”

Recognition and Excision Properties of 8‐Halogenated‐7‐Deaza‐2′‐Deoxyguanosine as 8‐Oxo‐2′‐Deoxyguanosine Analogues and Fpg and hOGG1 Inhibitors

“…Representative results obtained with hOGG1 are displayed in Figure 3A . [39][40][41] Figure 3B illustrates the results obtained for the duplex DNA containing Cl-deaza-dG and hOGG1. The binding kineticp arameters [association rate (k on )a nd dissociation rate (k off )] were calculated at the Fpg and hOGG1 concentrations used for the time course experiments by using the K d and k obs values, which are summarized in Ta ble 3.…”