Iyini i - nuclear magnetic resonance spectroscopy yamaprotheni?
I-nuclear magnetic resonance spectroscopy yamaprotheni (ngokuvamile i-protein NMR efushanisiwe) iyinkambu ye-biology yezakhiwo lapho i-NMR spectroscopy isetshenziselwa ukuthola ulwazi mayelana nesakhiwo kanye nokuguquguquka kwamaprotheni, kanye nama-nucleic acid, nezinkimbinkimbi zawo. Lo mkhakha waphayona nguRichard R. Ernst noKurt Wüthrich e-ETH, no-Ad Bax, uMarius Clore, u-Angela Gronenborn e-NIH, noGerhard Wagner eHarvard University, phakathi kwabanye. Ukuhlolwa kwesakhiwo nge-NMR spectroscopy ngokuvamile kuba nezigaba eziningana, ngasinye sisebenzisa isethi ehlukile yezindlela ezikhethekile kakhulu. Isampula liyalungiswa, kwenziwa izilinganiso, kusetshenziswe izindlela zokuhumusha, bese kubalwa futhi kuqinisekiswe isakhiwo.  I-NMR ihilela izakhiwo ze-quantum-mechanical zenhliziyo emaphakathi ("nucleus") ye-athomu. Lezi zakhiwo zixhomeke emvelweni yamangqamuzana endawo, futhi ukulinganiswa kwazo kunikeza ibalazwe lokuthi ama-athomu ahlanganiswe kanjani ngokwamakhemikhali, ukuthi asondelene kangakanani emkhathini, nokuthi ahamba ngokushesha kangakanani maqondana. Lezi zakhiwo ngokuyisisekelo ziyefana nalezo ezisetshenziswa ekubonisweni kwe-magnetic resonance imaging (MRI), kodwa izinhlelo zokusebenza zamangqamuzana zisebenzisa indlela ehlukile, efanelekile ekushintsheni kwesikali kusuka kumamilimitha (okubalulekile kuma-radiologists) kuya kuma-nanometer (ama-athomu axhunyiwe ngokuvamile ayingxenyana ye-nanometer), isici sesigidi. Lolu shintsho lwesikali ludinga ukuzwela okukhulu kokutholwa nokuzinza kokulinganisa kwesikhathi eside. Ngokungafani ne-MRI, izifundo zesakhiwo sezinto eziphilayo azivezi isithombe ngokuqondile, kodwa zithembela ekubalweni okuyinkimbinkimbi kwekhompyutha ukuze kukhiqizwe amamodeli wamangqamuzana anezinhlangothi ezintathu.  Okwamanje amasampula amaningi ahlolwe ngesisombululo emanzini, kodwa izindlela ziyasungulwa ukuze kusetshenziswe namasampula aqinile. Ukuqoqwa kwedatha kuxhomeke ekufakeni isampula ngaphakathi kukagesi onamandla, ukuthumela amasignali omsakazo ngesampula, nokukala ukumuncwa kwalawo masignali. Ngokuya ngemvelo yama-athomu ngaphakathi kweprotheni, i-nucleus yama-athomu ngamanye izomunca imvamisa ehlukahlukene yezimpawu zomsakazo. Ngaphezu kwalokho, izimpawu zokumunca zezinhlayiya ezahlukene zingase ziphazamiswe yizinhlayiya ezakhelene nazo. Lolu lwazi lungasetshenziselwa ukunquma ibanga phakathi kwama - nucleus. Lezi zindawo zingase zisetshenziselwe ukuthola isakhiwo seprotheni.  Ucwaningo olujwayelekile lungase luhlanganise indlela amaprotheni amabili asebenzisana ngayo, mhlawumbe ngenhloso yokuthuthukisa ama-molecule amancane angasetshenziselwa ukuhlola i-biology evamile yokuxhumana ("i-biology yamakhemikhali") noma ukuhlinzeka ngemikhondo engaba khona yokusetshenziswa kwemithi (ukuthuthukiswa kwezidakamizwa). Ngokuvamile, amaphrotheni amabili asebenzisanayo angase abonakale ngezifundo zezakhi zofuzo zabantu, okubonisa ukuthi lokhu kusebenzelana kungaphazanyiswa ukuguquka kwemvelo okungathandeki, noma angase adlale indima ebalulekile ekuziphileni okuvamile komzimba "oyisibonelo" njengempukane yezithelo, imvubelo, isibungu i-C. elegans, noma amagundane. Ukuze kulungiselelwe isampula, ngokuvamile kusetshenziswa izindlela ze-molecular biology ukuze kwenziwe amanani ngokuvutshelwa kwamagciwane. Lokhu kuvumela nokushintsha ukwakheka kwe-isotopic ye-molecule, okuyinto efiselekayo ngoba ama-isotopes aziphatha ngendlela ehlukile futhi anikeza izindlela zokukhomba amasignali e-NMR agqagqene.