I-Immunoglobulin G, kutheni ufuna umntu?

Zininzi izinto eziphendula ekulwa nokusuleleka kwintsholongwane yomzimba. Enye yezona ndawo zibaluleke kakhulu kule nkqubo yilezi zi-immunoglobulins, kwaye zichaneke ngakumbi, i-immunoglobulin G. Phakathi kwezinye iindidi ze-immunoglobulins, Ig Ig uyakwazi ukukhusela umntwana osanda kuzalwa kwiintsholongwane, njengoko unokukwazi ukungena kwigazi lomama nge-placenta, Ukuhamba kwegazi lomntwana.

I-molecule yeG Ig iqukethe i-subunit ubunzima bayo malunga ne-150 kD. Kubantu, kwakunye nakwiigundane, iikokisi ezine ezine-immunoglobulin G zichazwe. Baqala ukufunyanwa ngokusebenzisa iindlela zokwenza uphando lwe-serological. Ummandla we-hinge we-immunoglobulins ubonakaliswa nenani elikhulu leentsalela ze-cysteine kunye nama-molecule athambileyo, enquma ukuguquguquka kwawo. Ukudibanisa izibopho kule nxalenye ye-molecule zineenkcenkcesheka, ziqala kwi-subclass ye-globulin. Ngoko, i-Gamma 1 kunye neGamma 4 i-globulins zinamabhondi amabili e-disulfide, i-Gamma 2-yezine, i-Gamma 3-ishumi elinanye. Kuloluhlu lwe-Gamma 1, ummandla wengqimba uvela kuphela kwi-residu engama-216, kwaye uphela kuma-231-m. Kwaye i-hinge yommandla weGamma 3 wekhenkethi ikhona kwiminyaka engamashumi amane anesixhenxe emva kweGamma 1. Ukufundwa kwesi sihlandlo se-amino acid kwenza kube lula ukuba ukwanda kwentsalela kuhambelana nokuphindaphinda kabini kwecandelo le-Gamma 1 chain 216-231. Ummandla wendiza unomsebenzi obalulekileyo: ngenxa yokusebenzisana kwezi zibophelelo ezinzima, i-octapeptide eqinile kunye ne-cyclic ishicilelo eyenzeka njenge-axis yokujikeleza kuyo yonke indawo yendawo ye-hinge, kwaye ngenxa yoko iinqununu ze-Fab, eziyimfuneko kakhulu ekusebenzisaneni neentlobo ze-antigen.

Isizukulwana se-IgG senziwa ngexesha lokuphendula kwangasese kunye nokuzikhusela komzimba, kuba lolu hlobo lwe-antibody lusebenza ngokugqithiseleyo ukungena kwiifom, lubopha kwaye, emva koko, lususa ama-antigens angaphandle.

Ukukhuselwa kwe-antibacterial emzimbeni womntu unoxanduva olufanelekileyo lwe-immunoglobulin G. Ukwandisa olu hlobo lwe-globulin lunokuthi imeko apho umzimba wamasosha sele udibanisene nama-antigens angaphandle kwaye waqala ukuphuhlisa izikhuhlane zabo. Ngaloo ndlela, ukufumanisa ngokukhawuleza kwenyuka kwinani le-immunoglobulins kusenza siqale ukuxilongwa ngexesha kunye nokunyangwa kwezifo ezibangele iintlobo zeebhaktheriya kunye neentsholongwane.

Umsebenzi oyintloko walo hlobo lwe-immunoglobulin kukukhusela umzimba womntu kwiintengiso zangaphandle ezingabangela izifo ezithathelwanayo. I-Immunoglobulin G ibambana zombini kunye nezifo ezigugu ngokwabo, kunye nemveliso yomsebenzi wabo obalulekileyo ngo-opsonization, ukuqaliswa kweenkqubo ze-phagocytosis kunye nokuncoma.

I-Immunoglobulin G iyimpendulo ye-thymus, oko kukuthi, ihlanganiswe kwi- thymus (thymus), ngokubandakanyeka ngqo kwe-T-lymphocytes. Olu hlobo lwe-globulin luyinxalenye esemqoka yeqhekeza le-globulin yegazi kunye ne-akhawunti malunga ne-80% yazo zonke iintlobo ze-immunoglobulins. Ngaloo ndlela, ukusetyenziswa kwazo zonke iimpawu zokuzikhumbuza izifo, kunye ne-irradiation kwimeko engagxininisi kuphela ukuhlanganiswa kwe-Ig G, kodwa iyakunciphisa ngokupheleleyo.

I-Immunoglobulin G, isiqhelo salo emzimbeni ngokwahluka ngokuxhomekeke kwiminyaka yobudala, sifinyelela kumgangatho wokugqibela ngeminyaka eyi-15 kwaye i-8-17 grams nganye ilitha yegazi. Kule meko, i-immunoglobulins ayinakho kuphela kwiibhedi ze-vascular kwaye ijikeleza emzimbeni kunye negazi, iyakwazi ukufaka indawo engenabala, ngokuqala ukwenza yonke imisebenzi yayo. I-Immunoglobulin G isasazwa ngokusemthethweni kwisibhedlele se-vascular nangaphakathi kwamanye amathambo omzimba, ukuze umzimba ukhuselwe kwizifo.