Structure-function studies of human 5-alpha reductase type 2 using site directed mutagenesis
| Autor: | Sasa Trivic, Ian R Lee, Fiona O Baxter |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Stereochemistry
Endocrinology Diabetes and Metabolism medicine.medical_treatment Clinical Biochemistry Biology Transfection Biochemistry Steroid chemistry.chemical_compound Structure-Activity Relationship Endocrinology 3-Oxo-5-alpha-Steroid 4-Dehydrogenase medicine Structure–activity relationship Animals Humans Testosterone Amino Acid Sequence Site-directed mutagenesis Molecular Biology Peptide sequence DNA Primers chemistry.chemical_classification Base Sequence Mutagenesis Wild type Cell Biology Rats Enzyme chemistry Finasteride Mutagenesis Site-Directed Molecular Medicine |
| Zdroj: | The Journal of steroid biochemistry and molecular biology. 77(2-3) |
| ISSN: | 0960-0760 |
| Popis: | Site directed mutagenesis of human steroid 5alpha-reductase types 1 (5AR1) and 2 (5AR2) has been used to identify residues involved in inhibitor/substrate binding by 5AR2. Replacing residues 21-24 (GALA) in 5AR2 with the analogous residues 26-29 (AVFA) from 5AR1 did not significantly alter either the Km for testosterone or the Ki for the competitive inhibitor Finasteride. Replacement of AVFA in 5AR1 with GALA from 5AR2 however, significantly decreased the Km and increased the resistance to Finasteride. These findings confirm that 5AR1 residues 26-29 are involved in inhibitor/substrate binding but suggest residues 21-24 of 5AR2 are not. Replacing residues 20-29 (QCAVGCAVFA) of 5AR1 with the analogous residues 15-24 (ATLVALGALA) from 5AR2, changed the Km and Ki to values approaching those for wild type 5AR2. Replacing residues VAL in wild type 5AR2 with VGC from 5AR1 did not change Km or Ki but replacing ATL in 5AR2 with QCA from 5AR1 significantly decreased the Km and increased the resistance to Finasteride. Conversely, replacing QCA with ATL in 5AR1 containing GALA in place of AVFA, increased the Km and decreased resistance to Finasteride. These findings indicate residues 15-17 of human 5AR2 participate in inhibitor/substrate binding whereas residues 18-20 do not. |
| Databáze: | OpenAIRE |
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