Ngemva kweminyaka ecishe ibe yishumi yomzamo, ososayensi e-RIKEN baye banquma ukwakheka kweprotheyini ebalulekile ye-transporter esiza izitshalo ukuqoqa insimbi emhlabathini. Lokhu kutholakala kungase kuqondise ukuthuthukiswa kwezivundisi ezintsha ezinamandla amakhulu ezizosiza izitshalo ukukhipha insimbi emhlabathini ongenawo insimbi.
Cishe ingxenye yesithathu yawo wonke umhlaba ine-alkaline ngoba inhlabathi yawo inosawoti omningi we-alkaline, i-calcium carbonate. I-ayoni ayincibiliki kahle kule nhlabathi ene-alkali, futhi ukuntuleka kwe-iron okungaba umphumela kungakhinyabeza ukukhula kwezitshalo.
“Ukuthatha insimbi enhlabathini akulula,” kusho u-Atsushi Yamagata we-RIKEN Center for Biosystems Dynamics Research.
Nokho, utshani obuvamile, okuhlanganisa ukolweni nebhali, buye bashintsha isu eliyingqayizivele lokubamba insimbi. Bayakhulula amakhemikhali ebizwa ngokuthi ama-phytosiderophores adedelwa emhlabathini, lapho ebopha khona ngensimbi futhi enze inkimbinkimbi izitshalo ezingayithola ngezimpande zazo.
I-phytosiderophores yizinhlanganisela ezaziwa ngokuthi ama-mugineic acid. Ngenkathi bephethe insimbi yabo baphinde bafakwe kumaseli ezitshalo ngeprotheyini ye-transporter kulwelwesi lwamaseli. Kodwa okuningi akukaziwa mayelana nendlela amangqamuzana ale nqubo.
Manje, u-Yamagata kanye nozakwabo banqume ukwakheka kwephrotheni ye-transporter okokuqala ngqa.
"Sixazulule isakhiwo seprotheni ye-transporter-kokubili esimweni esingaboshiwe futhi lapho sihlanganiswa ne-iron-carrying phytosiderophore," kusho u-Yamagata. Lokhu kubalulekile ngoba kusiza abacwaningi ukuthi baqonde imininingwane emihle ye-molecular yokuthi kanjani iron-i-comtaining complex ixhumana ne-transporter okufanele ihanjiswe kumaseli.
Ithimba le-RIKEN belizama ukuthola ukwakheka kwephrotheni ye-transporter cishe iminyaka eyishumi. “Asikwazanga ngisho nokuthola amakristalu adingekayo ukuze ahlaziywe nge-X-ray crystallography,” kusho u-Yamagata. Impumelelo iqhamuke nentuthuko yakamuva yesu elibizwa ngokuthi i-cryo-electron microscopy, eyembula izakhiwo ngokudubula ama-electron kumasampuli afriziwe we amaprotheni.
Lolu cwaningo manje seluqondisa umsebenzi wokwenza okuphuma ku-mugineic acid, iqembu elikholelwa ukuthi kungaba isizukulwane esisha somanyolo osebenza kahle kakhulu enhlabathini ene-alkaline.
“Okuphuma ku-synthetic okukodwa, okuthuthukiswe umhlanganyeli wethu u-Kosuke Namba wase-Tokushima University, kungathuthuka. ukukhula kwezitshalo kangcono kunenhlanganisela yemvelo cishe cishe ingxenye eyinkulungwane yezindleko,” kusho u-Yamagata. Okubizwa nge-proline-2'-deoxymugineic acid (PDMA), okuphuma kokunye kuzinzile inyanga yonke inhlabathi, uma kuqhathaniswa nosuku kuphela lwenhlanganisela yemvelo.
I-Namba manje isebenza nomkhiqizi wase-Japan ukukhulisa ukukhiqizwa kwe-PDMA ukuze isetshenziselwe ukuhweba njengomanyolo wezolimo.