TRYPTOPHANE

From Big Medical Encyclopedia

TRYPTOPHANE — (Z-(Z-indolyl) - wasps-ami-nopropionovaya acid, indolalanine; in a human body and animals is not synthesized, treats irreplaceable amino acids. T. is molecular composition of proteins (see), including enzymes (see), and also is a biosynthetic predecessor of alkaloids (see), niacin (see), serotonin (see) and other biologically active agents. Lack of T. in a diet is a cause of infringement of protein synthesis, decrease in content of serotonin in a brain and other fabrics, it can lead also to development of a pellagra (see). At deficit of a pyridoxine (see) exchange of T is broken.: with urine the quantity of metabolites of T which is sharply increased against norm is distinguished. kynurenine and xanthurenic to - you. Disturbance of exchange of T. at the person can be primary, genetically caused, and secondary — at a disease of a liver and kidneys, at schizophrenia (see), maniac-depressive psychosis (see), epilepsies (see), a family ataxy of Fridreykh (see the Ataxy), Itsenko's diseases — Cushing (see Itsenko — Cushing a disease), collagenoses (see. Collagenic diseases), tuberculosis (see), diseases went. - kish. a path, anemias (see), nek-ry malignant tumors (see). To hereditary defects of exchange of T. belong Hartnup's disease (see Hart-nupa a disease) — disturbance of absorption of T. in intestines and a reabsorption of T. in kidneys; a so-called syndrome of «blue diapers» — disturbance of absorption of T. in intestines, prp it indigotin, allocated with urine is formed of two molecules of an indole (see) blue; Tada's syndrome — a tryptophanuria in combination with dwarfism (see); Price's syndrome — a kinureninuriya, a scleroderma (see); the hereditary ksantureninatsiduriya, at a cut is lowered activity of a kinureninaza (KF 3.7.1.3), the piridoksalfosfatza-visimy enzyme participating in exchange of T. Disturbance of exchange of T. it is established also at an allergic dermatosis (see). At plants of T. is a biosynthetic predecessor of alkaloids and other connections: harmin, a psilocybin, an indole of silt-3-acetate (auxin), whether-zerginsvoy acids (see), Reserpinum (see).

History of opening of T. is an interesting episode in studying and identification of amino acids (see). Already long before its opening in 1901 it was known that at tryptic digestion it is white


k (see Trypsin) it is possible to observe staining reaction with a bromine water, the edge does not appear neither with complete proteins, nor with products of acid hydrolysis of protein. This reaction was called «tryptophane howl» that is meant by «the reaction informing on splitting». It was established later that reaction happens to a bromine water only in the presence of free T., but not at acid hydrolysis, since, in acidic environment T. collapses.

Maintenance of T. in hemoglobin (see) and a myoglobin (see) the person is made by 1,9 and 3,6% respectively, in cytochrome from a horse (see Tsitokhro-my) — 1,5%, in insulin and ribonuclease T. no.

In a blood plasma of the person contents free T. from 0,4 to 3 mg fluctuate { 100 ml (on average 1 — 1,27 mg! 100 ml), and its concentration depends on extent of linkng with albumine. In phytalbumins T. it is less, than in animals. Maintenance of T. (in / 100 of protein) in meat averages — 1,2, in eggs — 1,4, fish — 0,8, cow's milk — 1,3, wheat flour — 1,3, potatoes — 0,9, peas — 0,7. The richest source of T. meat products (especially a liver), milk, eggs are.

Daily requirement of T. for children (depending on age) averages from 15 to 30 mg! kg, and for adults — 7 mg! kg. 60 mg of T accepted with food. 1 mg nicotinic to - you are equivalent (Niacinum).

Pier. weight (weight) of T. makes 204,22. At the heart of structure of T. the heterocyclic indole system representing as if the condensed benzene and pyrrol rings lies.



tryptophane

Hydrogen atom at nitrogen of a pyrrol ring has property to form bonds with flat molecules, and also with the groups localized in a globule of proteins. And a zoelektrichesky point (see). T. is at pH 5,89. In comparison with phenylalanine (see) and tyrosine (see). T. possesses stronger absorption in the UF-part of a range (the maximum of absorption is at the wavelength of 279 nanometers). As a part of live organisms only L-tryptophane meets (see the Isomerism). In the cleared look it represents colourless hexagonal leaflets. Ud. optical rotation (a)20 = — 33,7; * °pl 293 ° (with decomposition). Solubility (in / 100 ml) at 25 ° is equal in water 1,14, and at 75 ° — 2,79; T. we will dissolve in ethanol a little, it is insoluble on air. D-tryptophane


represents colourless crystals, (a)90 — = 4-32,9; g°pl 282 °. Racemic substance (see. Racemic connections) isomers T. has an appearance of colourless hexagonal plates, g°pl 283 °, a rastvorima in hot water, it is not enough rastvorim in a cold water and ethanol.

In a human body and animal T. arrives as a part of proteins of food. After absorption from intestines in blood the most part of T. it is used for biosynthesis of proteins. T. it is coded by a triplet At — uracil, guanine, guanine (see. Genetic code), and tryptophane promotes education and - spirals of protein, i.e. to formation of its secondary structure. Metabolism of T. it is carried out on a serotoninovo-m, indole and kinureninovy ways. Hydroxylation of T. leads to education 5 - gidroksitriptofa - on with its subsequent decarboxylation (see) to a 5-gidroksitripta-mine. Transmutation products of the last of 5 (hydras) oksiindoliluks-usny (OIUK) and 5-metoksiindoliluksus-naya to - you are excreted with urine, on this way the metaball iziru-tsya by 3% arrived with food T. Normal with urine of the person it is removed apprx. 5 mg of OIUK a day. At patients with malignant carcinoid (see) excretion of OIUK reaches 400 mg a day. In a liver and intestines of T. turns in triptamin, from to-rogo are formed indolyacetic and indolylpyroracemic to - you (see Activators of growth). Under the influence of a bacterial flora of a large intestine of T. is exposed to deamination (see) and to the subsequent disintegration of side chains with formation of skatole (see), a skatoksila, an indole, indoxyl. In intestines the indole can directly be formed of T. Kontsentration indoks the ilsulfata

in urine is an indicator of activity of a bacterial flora of intestines. And, at last, T. is oxidized to kynurenine, to-ry turns in anthranilic, kinurenovy, xanthurenic, quinolinic, picolinic to - you and other products allocated with urine, and their total quantity correspond to quantity metaboliziruyemy T. From quinolinic to - you in a human body and animals niko-tinamidny coenzymes are formed (see Nicotine amide hell enin dinucleotide).

Receive T. from tryptic hydrolyzates of proteins, and also by chemical synthesis.

For qualitative and quantitative test of T. in biol. material use various methods of a chromatography (see), and for quantitative definition use Gopkins's method (see Gopkins methods), or reaction with aromatic aldehydes (? dimethylaminobenzaldehyde, rast-


vorenny in concentrated sulphuric acid, at interaction with T. gives red-violet coloring, intensity to-rogo is proportional to the maintenance of T.), and also spektrofotometrichesky (see the Range about photometry) and electrophoretic (see the Electrophoresis) methods.

During the definition of security of an organism with rat anti-acrodynia factor use test with loading of T.: in urine of investigated determine content xanthurenic to - you after reception of 10 g of T. However the increased removal xanthurenic to - you not always happens to urine display of hypovitaminosis of Wb (see. Vitamin deficiency), and can depend on increase in the activity triptofanpirro-manholes (tryptophanes-2,3-dioxygenases; KF 1.13.11.11) catalyzing oxidation of T. with formation of L-formilkinurenina.

Bibliography: Berezov T. T. and To

rovkin B. F. Biological chemistry, M., 1982; Rapoport S. M. Medical biochemistry, the lane with it., page 54, etc., M., 1966; Ores V. K. Triptofan (normal and pathologies), L zit., 1973, bibliogr.; Whyte A., etc. Fundamentals of biochemistry, the lane with English, t. 1 — 3, M., 1981; T a d and To. and. lake of Vitamin of B6 of dependent xanthurenic aciduria, Tohoku J. exp. Med., v. 93, p. 115, 1967. A. M. Shaposhnikov.

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