INOSINIC ACIDS

From Big Medical Encyclopedia

INOSINIC ACIDS (synonym inosinic acids) — the mononucleotides consisting of the remains of purine base — hypoxanthine, a ribose and phosphoric to - you; are substrate in reactions of energy balance in a human body and animals.

The most important biol, function I. to. is that they are a buffer stage of biosynthesis of all purines and purine nucleotides; in an organism educations guanylic and adenylic to - t and the corresponding triphosphates and, therefore, all purine nucleotides in structure are a source nucleic acids (see).

Actually And. to. are inosine-monophosphate (IMF), containing one rest phosphoric to - you, inozindifosfaty (IDF), containing two rests phosphoric to - you, tsinozintrifosfaty (ITF), containing three rests phosphoric to - you. The nucleoside consisting of the remains hypoxanthine (see) and riboses (see), is called inosine:

IDF and ITF is similar to corresponding to adenosinephosphoric acids (see) belong to to vysokoergichesky connections (see), i.e. contain a large supply of free energy, regions it is freed during the eliminating of trailer phosphatic groups and used by an organism for completion of a metabolic cost.

And. to. contain in various fabrics of live organisms and can be received or from them, or way deaminations (see) corresponding adenosinephosphoric to - t.

Actually inosinic to - that (IMF) it is for the first time received by Yu. Libikh in 1847 from muscular extract. It represents siropoobrazny substance, easily a rastvorima in water, forms well crystallizing salts; IMF is besieged by alcohol, and also in the form of low solubility baric salt; it is optically active, in 2,5 N of HCl of [a]D it is equal — 18,5 °. In trace amounts of IMF it is found as a part of acceptor RNA (see. RNA ).

In vitro IMF receive from the crushed muscular tissue, to-ruyu maintain at the room temperature for transformation adenylic to - you in And. to. ITF receive from ATP by deamination of the last nitrogenous to - that. IDF can be received from ITF by means of enzymatic eliminating of trailer phosphatic group. For receiving and cleaning And. to. widely apply various methods of a chromatography (see).

Trailer phosphatic groups I. to. easily exchange, e.g., with the participation of enzyme of a nukleozidmonofosfatkinaza (KF 2.7.4.4) on reaction: IMF + NTF -> IDF + NDF, where NTF and NDF — nukleozidtrifosfat and nukleoziddifosfat (it, e.g., can be adenosinetriphosphate and adenosinediphosphate), and also with the participation of enzyme of a nukleoziddifosfatkinaza (KF 2.7.4.6) on reaction: IDF + NTF -> ITF + NDF.

Biosynthesis of IMF — see. Adenozinfosforny acids .



Bibliography: Debov S. S. Exchange of nucleic acids, in book: Chemistry and biochemistry of nucleic acids, under the editorship of I. B. Zbar-sky and S. S. Debov, page 121, M. — L., 1968; Mickelson A. Chemistry of nucleosides and nucleotides, the lane with English, M., 1966.

I. B. Zbarsky.

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