Abstract
One of the mutants of Streptomyces cholesterol oxidase with the Val121Ala mutation (V121A) was kinetically analysed. Although the reaction rate-substrate concentration curve of wild type follows a simple Michaelis-Menten equation, that of V121A is sigmoidal. The cooperativity was apparent and caused by non-ionic detergents that were used as a solvent of cholesterol. The concentration dependence of V121A on detergents was more significant than that of wild type, although the reaction rates of both enzymes decrease as the concentrations of detergents increase. Further experiments suggested that less hydrophobic interactions between V121A and detergents should be responsible for the apparent cooperativity. Since Val121 is in a hydrophobic loop located near the active site, the mutational effect is structurally discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 609-611 |
| Number of pages | 3 |
| Journal | Protein Engineering |
| Volume | 11 |
| Issue number | 8 |
| Publication status | Published - 1998 Aug |
| Externally published | Yes |
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Keywords
- Apparent cooperativity
- Cholesterol oxidase
- Mutational effect
- Non-ionic detergent
- Streptomyces
ASJC Scopus subject areas
- Molecular Biology
- Biochemistry
Cite this
Effect of non-ionic detergents on apparent enzyme mechanism : V121A mutant of Streptomyces cholesterol oxidase endowed with enhanced sensitivity towards detergents. / Nishiya, Yoshiaki; Yamashita, Mitsuo; Murooka, Yoshikatsu; Fujii, Isao; Hirayama, Noriaki.
In: Protein Engineering, Vol. 11, No. 8, 08.1998, p. 609-611.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of non-ionic detergents on apparent enzyme mechanism
T2 - V121A mutant of Streptomyces cholesterol oxidase endowed with enhanced sensitivity towards detergents
AU - Nishiya, Yoshiaki
AU - Yamashita, Mitsuo
AU - Murooka, Yoshikatsu
AU - Fujii, Isao
AU - Hirayama, Noriaki
PY - 1998/8
Y1 - 1998/8
N2 - One of the mutants of Streptomyces cholesterol oxidase with the Val121Ala mutation (V121A) was kinetically analysed. Although the reaction rate-substrate concentration curve of wild type follows a simple Michaelis-Menten equation, that of V121A is sigmoidal. The cooperativity was apparent and caused by non-ionic detergents that were used as a solvent of cholesterol. The concentration dependence of V121A on detergents was more significant than that of wild type, although the reaction rates of both enzymes decrease as the concentrations of detergents increase. Further experiments suggested that less hydrophobic interactions between V121A and detergents should be responsible for the apparent cooperativity. Since Val121 is in a hydrophobic loop located near the active site, the mutational effect is structurally discussed.
AB - One of the mutants of Streptomyces cholesterol oxidase with the Val121Ala mutation (V121A) was kinetically analysed. Although the reaction rate-substrate concentration curve of wild type follows a simple Michaelis-Menten equation, that of V121A is sigmoidal. The cooperativity was apparent and caused by non-ionic detergents that were used as a solvent of cholesterol. The concentration dependence of V121A on detergents was more significant than that of wild type, although the reaction rates of both enzymes decrease as the concentrations of detergents increase. Further experiments suggested that less hydrophobic interactions between V121A and detergents should be responsible for the apparent cooperativity. Since Val121 is in a hydrophobic loop located near the active site, the mutational effect is structurally discussed.
KW - Apparent cooperativity
KW - Cholesterol oxidase
KW - Mutational effect
KW - Non-ionic detergent
KW - Streptomyces
UR - http://www.scopus.com/inward/record.url?scp=0031867401&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031867401&partnerID=8YFLogxK
M3 - Article
VL - 11
SP - 609
EP - 611
JO - Protein Engineering, Design and Selection
JF - Protein Engineering, Design and Selection
SN - 1741-0126
IS - 8
ER -