I-Immunoglobulin G, kungani efuna umuntu?

Izici eziningi zithinta ukulwa nokutheleleka emzimbeni womuntu. Enye yezindawo ezibaluleke kakhulu kule nqubo ingukuthi i-immunoglobulins, futhi ibe yinkimbinkimbi, i-immunoglobulin G. Phakathi kwezinye izinhlobo ze-immunoglobulins, yi-Ig G ekwazi ukuvikela umzimba wezingane ezisanda kuzalwa, njengoba inamandla okungena ngegazi lomama ngokusebenzisa i-placenta, Ukugeleza kwegazi kwengane.

I-molecule Ig Ig iqukethe i-subunit isisindo sayo cishe 150 kD. Kubantu, kanye nasezimpini, kunezigaba ezine ezine-immunoglobulin G zichazwe. Zitholwe kuqala zisebenzisa izindlela zesayensi zokuphenya. Isizinda se-hinge se-immunoglobulins sibonakala ngenani elikhulu lezinsalela ze-cysteine ne-proline molecules, ezenza ukuthi ziguquguquke. Ukungcolisa izibopho kule ngxenye ye-molecule kunemibono yabo, kusukela ku-subclass ye-globulin. Ngakho, i-globulins yeGamma 1 neGamma 4 inezinhlobo ezimbili ze-disulfide, Gamma 2 - ezine, i-Gamma 3 - neshumi nanye. Kumaketanga we-Gamma 1, isifunda se-hinge sisuka kuphela ku-216, futhi siphela ku-231-m. Futhi isigaba se-hinge seGamma 3 sochungechunge sitholakala izikhathi ezingamashumi amane nesikhombisa emuva kweGamma 1. Ukucwaninga kwalokhu kulandelana kwe-amino acid kwenza kube lula ukuthatha ukuthi ukwanda okunjalo kwezinsalela kuhlotshaniswa nokuphinda kabili kwezingxenye zezinketho zeGamma 1 216-231. Isizinda se-hinge sinesici esibalulekile: ngenxa yokusebenzisana kwamaketanga amabili anzima, kuphakama isakhiwo esiqinile nesicacile se-octapeptide esisebenza njenge-axis of rotation kulo lonke isifunda se-hinge esifanayo, ngakho-ke ngenxa yezingxenye ze-Fab, okudingeka kakhulu ukusebenzisana nama-antigen ahlukahlukene.

Isizukulwane se-IgG senziwa ngesikhathi sokuphendula komzimba okuyisisekelo nomzimba wesibili, ngoba lolu hlobo lwe-antibody lusebenza ngokuphumelelayo kakhulu ukungena ezinhlobonhlobo, lubophezela futhi, ngokulandelayo, lususe ama-antigens angaphandle.

Ukuvikelwa kwe-antibacterial emzimbeni womuntu kunomthwalo wemfanelo ngokuqondile kwe-immunoglobulin G. Ukwandisa lolu hlobo lwe-globulin kungaba lapho amasosha omzimba asevele ehlangana nama-antigens angaphandle futhi aqala ukuthuthukisa ama-antibodies awo. Ngakho, ukutholakala okwesikhashana kwenyuka kwinani lama-immunoglobulins kusivumela ukuba siqale ukuxilongwa nokuphathwa kwezifo ezibangelwa ama- bacteria ahlukahlukene kanye nama-virus.

Umsebenzi oyinhloko walolu hlobo lwe-immunoglobulin ukuvikela umzimba womuntu kuma agent angaphandle angabangela izifo ezithathelwanayo. I-Immunoglobulin G ilwa kokubili ngamagciwane, kanye nemikhiqizo yomsebenzi wabo obalulekile nge-opsonization, ukuqaliswa kwezinhlelo ze-phagocytosis nokuncoma.

I-Immunoglobulin G iyinhloko ye-thymus, okungukuthi, ihlanganiswa ku- thymus (thymus), ngokubandakanyeka ngqo kwe-T-lymphocytes. Lolu hlobo lwe-globulin luyingxenye esemqoka yengxenyana ye-globulin yegazi kanye nama-akhawunti angama-80% azo zonke izinhlobo ze-immunoglobulins. Ngakho-ke, ukusetshenziswa kwazo zonke izifo zokuzivikela ezingenakwenzeka, kanye ne-irradiation esifundazweni akugcini nje ukucindezela ukuhlanganiswa kwe-Ig G, kodwa futhi ukuyiqeda ngokuphelele.

I-Immunoglobulin G, evamile emzimbeni ehluka kuye kuye yobudala, ifinyelela ezingeni layo lokugcina ngeminyaka engu-15 futhi i-8-17 amagremu ngalinye ilitha legazi. Kulesi simo, i-immunoglobulins ayikwazi ukuhlala kuphela embhedeni wamasongo futhi idlulisele emzimbeni kanye negazi, ingafaka kalula kalula isikhala esingenasisindo, iqala ukwenza yonke imisebenzi yawo eminingi. I-Immunoglobulin G isatshalaliswa ngokufanayo kokubili embhedeni wamasongo futhi ngaphakathi kwamanye ama-tissue womzimba, ukuze umzimba uvikelwe ezifweni.