ELASTIN — the fibrous protein making the ground mass of elastic fibers of connecting fabric. At a number of diseases, e.g. at to emphysema of lungs (see), pancreatitis (see), atherosclerosis (see) and others patol. states, there is a destruction E. as a result patol. proteolysis that is caused, obviously, disturbance fiziol. balance between elastases (see) and their inhibitors.
AA. the hl is synthesized. obr. smooth muscle cells (see. Muscular tissue ) and fibroblasts in the form of soluble protein — a tropoelastin about a pier. it is powerful (weight) apprx. 70 000. As a result of oxidizing deaminations (see) the remains lysine (see) in a polypeptide chain between monomers E. there are covalent intermolecular stitchings and so-called desmozina and izodesmozina are formed; the associates which are turning out at the same time and then fibers E. are insoluble even at rather rigid processing.
AA. mammals are represented by insoluble protein with hydrophobic properties, a part to-rogo is apprx. 70% of amino acids with unpolar side chains — glycine (see), alanine (see), proline (see), valine (see). Elastin is characterized by big stability: it we will not dissolve in water, diluted to-takh and alkalis even at 100 °, it is steady against effect of many proteolytic enzymes (see. Peptidgidrolaza ) also it is hydrolyzed only by specific elastases. Soluble E. (tropoelastin) receive from aortas of the animals who were contained on the diet made with an exception of salts of copper.
Quantitatively E. determine by residual protein content after autoclaving, processing by alkalis and to-tami for the purpose of removal of the accompanying proteins.
Bibliography: Berezov T. T. and Korovkin B. F. Biological chemistry, page 717, M., 1982; Foster J. A. Elastin structure and biosynthesis, Meth. Enzymol., v. 82, pt A, p. 559, 1982; Sandberg L. B., Soskel N. T. a. Leslie J. G. Elastin structure, biosynthesis, and relation to disease states, New Engl. J. Med., v. 304, p. 566, 1981.
V. O. Shpikiter.