1. Rats were maintained for 10 d on a semi-synthetic diet containing 700 g glucose or 700 g fructose/kg. Individual enzymic reactions in bile acid synthesis and metabolism were studied by measuring the 7alpha-hydroxylation of [4-14C]cholesterol, and 12alpha-hydroxylation of 7alpha-[6beta-3H]hydroxy-4-cholesten-3-one, the 26-hydroxylation of 5beta-[7beta-3H]cholestane-3alpha,7alpha-diol and the 6beta-hydroxylation of [3H]lithocholic acid in liver homogenates. 2. The serum cholesterol level was approximately the same in both groups of animals, but the serum triglyceride level was almost twice as high in the fructose-fed rats compared to the glucose-fed rats. 3. The 6beta-hydroxylation of [3H]ithocholic acid was increased by about 20% in the fructose-fed rats compared to the glucose-fed animals. The activities of the other enzymic reactions studied did not differ significantly between the two groups of animals. The findings are discussed in relation to previous knowledge concerning mechanisms regulating triglyceride, pre-beta-lipoprotein and bile acid synthesis.
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JDS Commun
January 2025
Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210.
In this study, a thermostable β-galactosidase from OSU-PECh-4A has been isolated through diafiltration and size-exclusion chromatography. The enzyme consists of a heterodimer with a molecular mass of 110 kDa, with a small and large subunit of 36 and 74 kDa, respectively. The Michaelis constant (K) and maximum velocity (V) values for lactose and -nitrophenyl-β-d-galactopyranoside (NPG) hydrolysis were, respectively, 29.
View Article and Find Full Text PDFActa Naturae
January 2024
St Petersburg University, St. Petersburg, 199034 Russian Federation.
Living organisms exhibit an impressive ability to expand the basic information encoded in their genome, specifically regarding the structure and function of protein. Two basic strategies are employed to increase protein diversity and functionality: alternative mRNA splicing and post-translational protein modifications (PTMs). Enzymatic regulation is responsible for the majority of the chemical reactions occurring within living cells.
View Article and Find Full Text PDFArch Endocrinol Metab
January 2025
Unidade de Endocrinologia Ginecológica Hospital de Clínicas de Porto Alegre Divisão de Endocrinologia Porto AlegreRS Brasil Unidade de Endocrinologia Ginecológica, Divisão de Endocrinologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil.
Objective: To assess the genotypic and allelic distribution of the rs10046 polymorphism in the gene and evaluate whether this aromatase gene variant is associated with cardiovascular risk in postmenopausal women.
Materials And Methods: This cross-sectional study analyzed repository-stored samples from 370 postmenopausal women aged 44-72 years. Clinical, metabolic, and hormonal data were collected.
Angew Chem Int Ed Engl
January 2025
University of Oxford, Chemistry, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
The catalytic action of enzymes of a cascade trapped within a mesoporous electrode material is simultaneously energized, controlled and observed through the efficient, reversible electrochemical NAD(P)(H) recycling catalyzed by one of the enzymes. In their nanoconfined state, nicotinamide cofactors are tightly channeled current carriers, mediating multi-step reactions in either direction (oxidation or reduction) with a rapid response time. By incorporating a hydrogen‑borrowing enzyme pair, the internal action of which opposes the external voltage bias driving oxidation or reduction, a reduction process can be performed under overall oxidizing conditions, and vice versa.
View Article and Find Full Text PDFChemistry
January 2025
Karlsruhe Institute of Technology, Institute for biological interfaces 1 (IBG-1), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, GERMANY.
Enantioselectivity is a key advantage of enzymatic catalysis. Understanding the most important factors influencing enantioselectivity necessitates thorough investigation for each specific enzyme. In this study, we explore various approaches to optimize reaction conditions for organosilicon production using an immobilized Cytochrome C recently tailored via directed evolution.
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