TY - JOUR
T1 - Steroid 5α reductase in cultured human fibroblasts. Biochemical and genetic evidence for two distinct enzyme activities
AU - Moore, R. J.
AU - Wilson, J. D.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1976
Y1 - 1976
N2 - Various properties of the steroid 5α reductase have been examined in cell free extracts of skin and of fibroblasts cultured from genital and nongenital skins from control subjects and from patients with several forms of male pseudohermaphroditism. When 20α hydroxy 4 [1,2 3H] pregnen 3 one was used as substrate, two 5α reductase activities could be demonstrated in intact skin and cultured fibroblasts. The major activity, previously described for microsomes from human prepuce and extracts of cultured foreskin fibroblasts, is characterized by a narrow pH optimum near 5.5 and is limited to fibroblasts derived from genital skin. A second activity, not limited by the site of biopsy, has been demonstrated over a higher and broader range of pH (from 7 to 9); this enzyme activity is found in both genital and nongenital skin and in fibroblasts cultured from all skin regions. Whereas there is wide variability in the activity at pH 5.5 in genital skin fibroblasts, the activity at pH 7 to 9 is similar in fibroblasts derived from all anatomical sites. The two activities exhibit different kinetics with respect to steroid substrate and are also dissimilar in their subcellular distributions. Other properties, such as coenzyme requirement, steroid substrate specificity, and instability with increasing temperature, appear to be similar.
AB - Various properties of the steroid 5α reductase have been examined in cell free extracts of skin and of fibroblasts cultured from genital and nongenital skins from control subjects and from patients with several forms of male pseudohermaphroditism. When 20α hydroxy 4 [1,2 3H] pregnen 3 one was used as substrate, two 5α reductase activities could be demonstrated in intact skin and cultured fibroblasts. The major activity, previously described for microsomes from human prepuce and extracts of cultured foreskin fibroblasts, is characterized by a narrow pH optimum near 5.5 and is limited to fibroblasts derived from genital skin. A second activity, not limited by the site of biopsy, has been demonstrated over a higher and broader range of pH (from 7 to 9); this enzyme activity is found in both genital and nongenital skin and in fibroblasts cultured from all skin regions. Whereas there is wide variability in the activity at pH 5.5 in genital skin fibroblasts, the activity at pH 7 to 9 is similar in fibroblasts derived from all anatomical sites. The two activities exhibit different kinetics with respect to steroid substrate and are also dissimilar in their subcellular distributions. Other properties, such as coenzyme requirement, steroid substrate specificity, and instability with increasing temperature, appear to be similar.
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M3 - Article
C2 - 9407
AN - SCOPUS:0017102092
SN - 0021-9258
VL - 251
SP - 5895
EP - 5900
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 19
ER -