2007 Fiscal Year Final Research Report Summary
Recruitment of plastic-degrading enzymes onto the surface of plastics via fungal hydrophobin RolA
| Project/Area Number |
18580324
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Boundary agriculture
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| Research Institution | Tohoku University |
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Principal Investigator |
ABE Keietsu Tohoku University, Graduate Schhol of Agricultural Science, Associate Professor (50312624)
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| Co-Investigator(Kenkyū-buntansha) |
HONDOH Hironari Ritsumeikan University, Department of Physical Science, lecturer (10368003)
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| Project Period (FY) |
2006 – 2007
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| Keywords | hydrophobin / RolA / Aspergillus oryzae / interaction / solid-liquind interface reaction / biodegradable plastic |
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| Research Abstract |
When fungi grow on plant or insect surfaces coated with wax polyesters that protect against pathogens, the fungi generally form aerial hyphae to contact the surfaces. Aerial structures such as hyphae and conidiophores are coated with hydrophobins, which are surface-active proteins involved in adhesion to hydrophobic surfaces. When the industrial fungus Aspergillus oryzae is cultivated in a liquid medium containing the biodegradable polyester polybutylene succinate-coadipate (PBSA), the rolA gene encoding Type I hydrophobin RolA is highly transcribed. High levels of RolA are localized on the cell surface and also secreted into the liquid medium. Under these conditions, A. oryzae simultaneously produces the cutinase CutL1, which hydrolyzes PBSA. RolA adsorbed to the hydrophobic surface of PBSA particles in the medium recruits CutL1, resulting in condensation of CutL1 on the PBSA surface and consequent stimulation of PBSA hydrolysis (1, 2). The ability that RolA attached to the PBSA surfaces recruits esterase CutL1 is a newly discovered function in hydrophobin. In the present study, we studied amino acid residues involved in the RolA-CutL1 interaction by means of site-directed mutagenesis and chemical modification. Teflon particles (average diameter 100-200 nm) were coated with RolA and its derivatives. The Teflon particles coated with RolA or its derivatives were incubated with soluble CutL1 and the supernatant and particles were separated by centrifugation. Recruited CutL1 was extracted from the centrifuged particles with SDS and quantitatively measured by SDS-PAGE analyses. We found that His32 of RolA is an important amino acid residue required for RolA-CutL1 interaction.
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