2000 Fiscal Year Final Research Report Summary
Studies on the Molecular Mechanisms of the Formation of Azole Resistant Mutants of Pathogenic Fungi
| Project/Area Number |
10672081
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biological pharmacy
|
|---|
| Research Institution | Mukogawa Women's University |
|---|
Principal Investigator |
YOSHIDA Yuzo Mukogawa Women's University, School of Pharmaceutical Sciences, Professor, 薬学部, 教授 (70085281)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
AOYAMA Yuri Soka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (00158718)
|
|---|
| Project Period (FY) |
1998 – 2000
|
| Keywords | Azole antifungal agent / Cytochrome P450 / Drug resistance / Mutation / Sterol biosynthesis inhibitor / Azole resistant fungus / CYP51 / Candida albicans |
|---|
| Research Abstract |
Molecular and genetic mechanisms emerging an azole-resistant fungi were studied focusing on the alteration of the target enzyme, CYP51, by using an azole resistant isolate of Candida albicans named DUMC136 as a material. Analysis of CYP51 genes of DUMC136 and an azole-sensitive C.albicans ATCC 90028 revealed that DUMC136 was a homozygote of an altered CYP51, whereas CYP51 of ATCC 90028 showed allelic variation. This fact suggests that formation of the homozygote of an altered CYP51, which encodes azole-resistant CYP51 enzyme, may be the reason for azole resistance of DUMC136. The CYP51 alleles of ATCC 90028 named CYP51_<ATCC 90028-1> and CYP51_<ATCC 90028-2> and the altered CYP51 of DUMC136 named CYP51_<DUMC> were cloned and expressed in E.coli. The expressed CYP51s, CYP51_<ATCC 90028-1>, CYP51_<ATCC 90028-2> and CYP51_<DUMC>, were purified and characterized. No essential difference was observed between the enzymatic and spectrophotometric characteristics of CYP51_<ATCC 90028-1> and CY
… More
P51_<ATCC 90028-2>. However, catalytic activity and fluconazole susceptibility of CYP51_<DUMC> were significantly lower than those of CYP51_<ATCC 90028-1> and CYP51_<ATCC 90028-2>. It was also found that spectrophotometric characteristics of CYP51_<DUMC> such as the absorption maximum of the Soret band of the oxidized form and the spectral change induced by the interaction with fluconazole were different from those of the wild-type enzyme. These findings clearly indicate that the structural change caused by the two amino acid substitution observed between CYP51_<DUMC> and CYP51_<ATCC 90028-2> reduced the azole susceptibility of CYP51_<DUMC>. Recent X-ray crystallographic analysis of CYP51 of Mycobacterium tuberculosis revealed that the helix C region that includes above-mentioned two amino acid residues is a critical region affecting the structure of heme pocket of this enzyme. Consequently, azole resistance of CYP51_<DUMC> may be due not to the interaction between the substituted amino acids with azole compound but to the amino acid change in the C helix region. Less
|
-
-
-
-
-
-
-
-
[Publications] Aoyama, Y., Kudo, M., Asai, K., Okonogi, K., Horiuchi, T., Gotoh, O.and Yoshida, Y.: "Emergence of Fluconazole-Resistant Sterol 14-Demethylase P450 (CYP51) in Candida albicans Is a Model Demonstrating the Diversification Mechanism of P450."Arch.Biochem.Biophys.. 379. 170-171 (2000)
Description
「研究成果報告書概要(欧文)」より
-
[Publications] Hori, K., Sakaguti, A., Kudo, M., Ishida, K., Aoyama, Y.and Yoshida, Y.: "Structure-activity Relationships of a New Antifungal Imidazole, AFK-108, and Related Compounds."Chem.Pham.Bull.. 48. 60-64 (2000)
Description
「研究成果報告書概要(欧文)」より
-
-
[Publications] Asai, K., Tsuchimori, N., Okonogi, K., Perfect, J.R., Gotoh, O.and Yoshida, Y.: "Formation of Azole-resistant Candida albicans by Mutation of Sterol 14-Demethylase P450."Antimicrob, Agents Chemother.. 43. 1163-1169 (1999)
Description
「研究成果報告書概要(欧文)」より
-
