AMINOKISLOTAHO

AMINOKISLOTAHO, sinfi payvasthoi organiki, ki dar tarkibashon guruhi karboksil ( – SOON) va aminoguruh (– NH2) mavjud ast. A. khosiyati kislotagi va asosi dorand. Vobasta az sokhtor A. alifati va aromati meshavand. CHand navi A.-i alifati, mas., α –, β –, γ – va g. malumand. Az α – aminokislotaho safedaho va peptidho tarkib yoftaand. Onho dar amaliyoti muhimmi biologi ishtirok mekunand.
A. moddahoi kristallii berang buda, dar ob nagz hal meshavand. Bisyori onho tami shirin dorand. A. moddahoi amfoterand , binobar in beshtar dar namudi ioni duzaryada duchor meoyand.
Manbai asosii α – aminokislotaho baroi organizmhoi zinda safedai gizo meboshad. Bisyor α – aminokislotahoro khudi organizm sintez mekunad. A.-ero, ki az berun ba organizm vorid meshavand, A.-i ivaznashavanda menomand (mas., valin, leytsin, izoleytsin, lizin, treonin, metionin, fenilalanin, triptofan va g.). Hangomi baze bemoriho, khosa bemorihoi modarzodi, adadi A.-i ivaznashavanda meafzoyad. CHunonchi, hangomi bemorii fenilketonuriya organizm tirozinro sintez namekunad. Talaboti shaboruzii A.-i ivaznashavanda baroi odami kalonsol taqr. 1 g ast. Mafhumi «ivaznashavanda» to andozae shartist. Mas., tirozin dar organizm faqat az fenilalanin hosil megardad. Binobar in on mahz dar surati norasoii fenilalanin ivaznashavanda ast. Az tarafi digar, mavjudiyati tirozin dar gizo talabotro ba fenilalanin kohish medihad. CHunin hambastagi bayni metionin va sistein (sistin) niz vujud dorad. Hangomi norasoii A. dar khurok (triptofan, lizin, metionin) sintezi safeda va bisyor moddahoi zarurii organizm gayriimkon ast
A. dar organizm baroi sintez va resintezi safeda, hamchunin gormonho, aminho, alkaloidho, kofermentho, pigmentho va g. zarurand. A.-i ziyodati to mahsuli vopasini mubodila (dar odam va shirkhurho to mochevina, SO2 va ob) tajziya meshavand (hangomi on energiyai baroi faoliyati hayot zarur ikhroj megardad).
Baze A.-ro az mahsuli gidrolizi safedaho judo mekunand. Mac., kislotai glutaminatro az kazein, tirozinro az fibroini abreshim, argininro az jelatina, gistidinro az safedai khun va g. A.-i digarro bo rohi sintez (mas., kislotai glutaminat, metionin, lizin) hosil menamoyand.
Odam bo peshob dar yak shaboruz taqr. 1 g A.-i ozod khorij mekunad. Sababi afzoishi A. dar tarkibi peshob (aminoatsiduriya) bemorii giperaminoatsidemiya va baze amrozi irsi ast. Mas., dar mavridi sistinuriya sistine, ki bad hal meshavad, dar peshob dar shakli kristallho boqi memonad. Bo peshob barziyod ikhroj gashtani gistidin (gistidinuriya) boshad, asosan hangomi homilagi rukh menamoyad.
A. dar tib baroi molijai bemorihoi azoi hozima, jigar, kamkhuni, sukhta, reshi meda va g. muhim meboshand. Kislotai glyutaminat dar sohai ravonpizishki korbast meshavad. Metionin baroi tabobati farbehi, sirroz va dig. amrozi jigar mufid ast. Bo gistidin zakhmi meda va dig. bemorihoi rohi medayu rudaho tabobat meyoband. Dar surati dar organizm barziyod budani baze A. va norasoii A.-i digar holati zahroldi ba vuqu meoyad.
Ad.: Grandberg I.I., Organicheskaya khimiya, M., 1974; Tyukavkina N.A., Baukov YU.I., Bioorganicheskaya khimiya, M., 1985; Filippovich YU.B., Osnovi biokhimii, M., 1995.
SH. Samiev.