Elucidation of molecular mechanism for species specificity of Psm

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K15693
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including mycology)
• Research Institution: Matsuyama University
• Principal Investigator: Sekiya Hiroshi 松山大学, 薬学部, 助教 (70454890)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 溶菌酵素 / 細胞壁 / クロストリジウム / ウェルシュ菌

Outline of Final Research Achievements

Lytic enzymes that hydrolyze the cell wall of bacteria lyse and kill the bacteria. The lytic enzyme Psm has a strong lytic activity specifically for Clostridium perfringens, but its molecular mechanism is not well understood. Psm shows no lytic activity unless it binds to C. perfringens. In this study, it was revealed that teichoic acid, which is a constituent of cell wall, influences the binding of Psm. In addition, C. difficile is a problem in the medical field. Therefore, the cell wall binding domain of Psm and the cell wall binding domain of the lytic enzyme of C. difficile were recombined. However, the chimeric enzyme prepared this time did not show lytic activity against C. difficile.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

溶菌酵素は細胞壁の構成成分であるペプチドグリカンを直接的に加水分解するため、菌に作用すると細胞質成分が菌体外に漏出し、菌は瞬時に死に至るため、従来の抗菌薬よりも耐性菌が出現する可能性は極めて低いと考えられる。そこで、私は溶菌酵素が抗菌薬に代わる有力な治療薬のひとつになるのではないかと考え、ウェルシュ菌に特異的に強力な溶菌活性を示す溶菌酵素Psmの菌種特異性に関する分子メカニズムを明らかにすることを目指した。本研究で得られた知見から、強い溶菌活性を保持したまま任意の菌種に溶菌活性を示すキメラ酵素の構築が期待される。