ETHERIFICATION — reaction of formation of esters by interaction of acids or their derivatives with alcohols. Reaction, the return E. and consisting in gidro-
lytic splitting of an ester group with formation of alcohol and carboxylic to - you, are called saponification (see). Etherification is one of the most widespread exchange reactions of substances and energy in an organism (see the Metabolism and energy). The mechanism of effect of many enzymes (see), including seri-new proteinases (see Peptid-gidro-lazy), includes an obligatory stage E. Acylation of glycerin (see) fat to-tami leads to formation of its esters (see Triglycerides), so-called neutral fats (see). Etherification of nucleosides and sugars phosphoric to - that (see. Phosphoric acids) leads, respectively, to formation of nucleotides and phosphoric ethers of sugars. AA. histones (see) and fermental proteins under the influence of phosphoric to - you (see Phosphorylation) treat the most effective regulatory mechanisms of cellular exchange. Process E. it is widely used in chemical laboratories, pharmaceutical industry and in organic synthesis for receiving esters (see).
With disturbance of the normal course of reactions E. in an organism emergence of a row patol is connected. states. Positive correlation between a lipidemia (see the Lipemia) and ability of enzymes of a blood plasma to etherify cholesterol (see) is revealed. At lipidoses (see) process E., as a result to-rogo fats are formed, becomes irreversible. AA. fat to - the t of a blood plasma is braked at a diabetes mellitus (see a diabetes mellitus), nefroza, at starvation, an emotional stress. Oncogenous viruses (see), «imposing» to cells of a mistake in reaction E., cause their malignancy. So, the oncogene of a virus of sarcoma of Raus representing enzyme a protein kinase (see Kinases), phosphorylates proteins on the remains of tyrosine (see), but not on the remains of serine (see) and threonine (see), as in normal tags.
Bibliography: Gena Eukariot. (Unique genes), under the editorship of JI. JI. Kiselyova, page 117, M., 1982; M e c of l e r D. Biokhimiya, the lane • with English, t. 1 — 3, M., 1980; Moss D. U. both Butterworth of P. J. Enzimolo-giya and medicine, the lane with English, M., 1978.
E. V. Ramensky.