CHOLESTEROL ESTER HYDROLYSIS BY HOMOGENATES OF WHOLE TESTIS, SEMINIFEROUS TUBULES AND INTERSTITIAL CELLS OF MATURE RATS

1977 ◽  
Vol 75 (2) ◽  
pp. 235-243 ◽  
Author(s):  
J. P. RENSTON ◽  
T. J. IHRIG ◽  
R. H. RENSTON ◽  
B. GONDOS ◽  
R. J. MORIN
Keyword(s):  
Cholesterol Ester ◽  
Incubation Temperature ◽  
Hydrolytic Activity ◽  
Interstitial Cells ◽  
Seminiferous Tubules ◽  
Cholesterol Ester Hydrolase ◽  
Ester Hydrolase ◽  
Optimum Ph ◽  
Hormone Biosynthesis ◽  
Hydrolysis Of

The characteristics and localization of a cholesterol ester hydrolase enzyme in homogenates of whole testis and in isolated seminiferous tubules and interstitial cells of mature rats have been investigated. Hydrolysis of cholesteryl [1-14C]oleate occurred at an optimum pH of 7·0 was linearly related to time up to 5–6 h of incubation and increased linearly up to 0·25 mg protein/incubation. Hydrolytic activity was inhibited by increasing the incubation temperature from 29 to 41 °C and by sonication. Cholesterol ester hydrolase activity/mg protein was three times greater in homogenates of seminiferous tubules than in interstitial cells. Cholesterol ester hydrolase may function to provide precursors for use in seminiferous tubular steroid hormone biosynthesis or germ cell maturation.

scholarly journals Properties of a new fungal b-galactosidase with potential application in the dairy industry

1999 ◽  
Vol 30 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Rubens Cruz ◽  
Vinícius D'Arcádia Cruz ◽  
Juliana Gisele Belote ◽  
Marcelo de Oliveira Khenayfes ◽  
Claudia Dorta ◽  
...  
Keyword(s):  
Hydrolytic Activity ◽  
Industrial Applications ◽  
Transferase Activity ◽  
Optimum Temperature ◽  
Milk Whey ◽  
Beneficial Effects ◽  
Optimum Ph ◽  
Semi Solid ◽  
Good Productivity ◽  
Hydrolysis Of

<FONT FACE="Symbol">b</font>-Galactosidase or <FONT FACE="Symbol">b</font>-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of <FONT FACE="Symbol">b</font>-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.

scholarly journals Regulation of cholesterol ester hydrolase by cyclic AMP-dependent protein kinase

FEBS Letters ◽  
1986 ◽  
Vol 201 (2) ◽  
pp. 257-261 ◽  
Author(s):  
Roger J. Colbran ◽  
Andrew J. Garton ◽  
Susan R. Cordle ◽  
Stephen J. Yeaman
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Cholesterol Ester ◽  
Dependent Protein Kinase ◽  
Cholesterol Ester Hydrolase ◽  
Ester Hydrolase ◽  
Dependent Protein

Proposed Treatment for Infants With Wolman Disease

PEDIATRICS ◽  
1989 ◽  
Vol 83 (6) ◽  
pp. 1074-1075
Author(s):  
MOSHE WOLMAN
Keyword(s):  
Lysosomal Enzyme ◽  
Cholesterol Ester ◽  
Reticuloendothelial System ◽  
Cholesterol Esters ◽  
Enzyme Molecule ◽  
Acid Lipase ◽  
Wolman Disease ◽  
Cholesterol Ester Hydrolase ◽  
Ester Hydrolase ◽  
Available Information

Presently available information indicates that Wolman disease is due to a defect in a single lysosomal enzyme molecule, called acid lipase, esterase, or cholesterol ester hydrolase (EC3.1.1.13). Cells of the reticuloendothelial system, hepatocytes, adrenocortical, and presumably many other cells normally, contain a neutral esterase associated with their microsomes, which is not deficient in Wolman disease. Theoretically, catabolism of intracellular hydrophobic cholesterol (esters and triglycerides) should proceed normally in Wolman disease cells whenever the metabolic chain does not depend on lysosomal hydrolysis.

scholarly journals The Critical Role of Neutral Cholesterol Ester Hydrolase 1 in Cholesterol Removal From Human Macrophages

2010 ◽  
Vol 107 (11) ◽  
pp. 1387-1395 ◽  
Author(s):  
Masaki Igarashi ◽  
Jun-ichi Osuga ◽  
Hiroshi Uozaki ◽  
Motohiro Sekiya ◽  
Shuichi Nagashima ◽  
...  
Keyword(s):  
Cholesterol Ester ◽  
Critical Role ◽  
Cholesterol Removal ◽  
Human Macrophages ◽  
Cholesterol Ester Hydrolase ◽  
Ester Hydrolase
Sign in / Sign up

Export Citation Format

Share Document