Detail of "4090-29-3"

Reference

A one-step enzymatic assay for the measurement of 17b-hydroxy and 17-oxo steroid profiles in biological samples

A one-step enzymatic assay for the measurement of 17b-hydroxy and 17-oxo steroid profiles in biological samples. Payne, Donna W.; Talalay, Paul (Sch. Med., Johns Hopkins Univ., Baltimore, MD 21205, USA). J. Steroid Biochem., 25(3), 403-10 (English) 1986. CODEN: JSTBBK. ISSN: 0022-4731. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) A simple enzymic method is described for the sensitive and specific detection and quantitation of families of hydroxy- and oxo-steroids in biol. mixts. Anal. of the profiles of individual steroids may be achieved following their chromatog. sepn. The method employs highly purified and active bacterial hydroxy steroid dehydrogenases (HSD) which promote stereospecific, nicotinamide nucleotide-dependent oxidns. and redns. at specified positions of steroids. In the presence of catalytic quantities of steroids these enzymes promote the transfer of H (transhydrogenation) between NADH [58-68-4] and NAD [53-84-9] analogs. A recently purified 17b-HSD [9028-61-9] from an Alcaligenes species shows almost complete specificity for the 17b-hydroxy- and 17-oxo-groups of both C18 C19 steroids. This enzyme catalyzes steroid-dependent transhydrogenation between NADH and the thionicotinamide analog of NAD (S-NAD) [4090-29-3]. When these components are incubated at pH 8.5 in the presence of minute quantities of steroid substrates, S-NADH [1921-48-8] (measured at 398 nm where NADH does not absorb) accumulates at a const. rate which is proportional to the concns. of steroid and enzyme. The linear increase in absorbance with time is a measure of the total concn. of 17b-hydroxy- and 17-oxo-steroids, and can be used to detect subpicomol quantities of steroids. The method is illustrated by the detection and identification of free and conjugated androgens in human serum following their sepn. by HPLC. The specificity of the transhydrogenase assay is completely dependent on the specificity of the enzyme and is thus applicable to the detection of other hydroxy- and oxo-steroids by making use of HSDs with appropriate specificities. The simple 1-step reaction lends itself to automation, needs no auxiliary detection systems, and requires only an inexpensive colorimeter.

Effects of NAD+ analogs on the iodoacetate modification of D-glyceraldehyde-3-phosphate dehydrogenase and enzymic hydrolysis of acetyl phosphate

Effects of NAD+ analogs on the iodoacetate modification of D-glyceraldehyde-3-phosphate dehydrogenase and enzymic hydrolysis of acetyl phosphate.Some chemicals with cas registry numbers like 4090-29-3 and 5624-35-1 are also used. Xu, Gongqiao; Zou, Chenglu (Inst. Biophys., Acad. Sin., Beijing, Peop. Rep. China). Shengwu Huaxue Yu Shengwu Wuli Xuebao, 15(6), 569-75 (Chinese) 1983. CODEN: SHWPAU. ISSN: 0582-9879. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) Both the rate of iodoacetate modification of D-glyceraldehyde 3-phosphate dehydrogenase and the rate of hydrolysis of acetyl-phosphate as catalyzed by the same enzyme are greatly accelerated by NAD. The effects of a no. of NAD analogs on these 2 reactions were compared. Among the NAD analogs tested, 3-carboxypyridine adenine dinucleotide (CPAD) and 3-formylpyridine adenine dinucleotide (FPAD), which are inactive as hydrogen acceptors, reduced the rate of carboxymethylation of apo-D-glyceraldehyde 3-phosphate dehydrogenase by iodoacetate, whereas all the active analogs, 3-acetylpyridine adenine dinucleotide (APAD), nicotinamide guanine dinucleotide (NGD), and 3-aminothioxomethylpyridine adenine dinucleotide (TPAD), like NAD itself, increased the rate of iodoacetate modification. The effects of these analogs on the rate of hydrolysis of acetyl-phosphate as catalyzed by the o-iodosobenzoate-treated apoenzyme are somewhat different; CPAD and TPAD had no effect, whereas NGD, APAD, and FPAD, like NAD, increased the rate of this catalytic reaction. The behavior of these NAD analogs in this reaction is in accord with their capacity for the formation of fluorescent derivs. when UV irradiated with the carboxymethylated enzyme. .