Te kahurangi metilīni me ngā mitokōria: te kawe irahiko me ngā taunakitanga

Whakaarohia ētahi tauira whakamātautau e rua e noho pātata ana. Kei roto i ēnei e rua he mitokōria roro kua whakakinotia ki te rotenone, he matū e aukati ana i te Matatini I o te mekameka hā. Ka tāpirihia e te kairangahau he horopeta micromolar o te kahurangi metilīni ki tētahi mā te pipete. Ka hoki mai tētahi wāhanga o te whakamahinga hāora. Ka hoki mai tētahi wāhanga o te ngaohiko kiriuhi. Ka tīmata anō he wāhanga iti o te waihanga ATP. I te ipu ine e pātata ana, ka whakaatu tētahi pūoko perōkisa i tērā atu haurua o te kōrero: kua tini whakarea te putanga hauwai perōkisa, i ia horopeta i whakamātauria, i raro i ia tïpako i whakamahia.

He tika ngā pānuitanga e rua. He kaikawe irahiko te kahurangi metilīni e taea ai te rere tonu o te ia huri noa i tētahi wāhanga kua pakaru o te mekameka hā, ā, he utu perōkisa tō taua kawe. Ki te mau tahi ēnei meka e rua ki te hinengaro, ka mārama ngā tuhinga rangahau mō te pānga o te kahurangi metilīni ki te mahi mitokōria. Ki te mau koe ki tētahi anake, ka rite te kōrero ki te merekara, ki te mōrearea rānei, i runga i te pepa i pānuitia tuatahitia e koe.

Te kaikawe irahiko, kia mārama te kōrero

He rārangi tuku whakawhiti te mekameka hā. Ka uru ngā irahiko ki te Matatini I (mai i te NADH), ki te Matatini II rānei me ngā whākōkī flavin e hāngai ana (mai i te succinate me ētahi atu kaituku rite), ka whakawhiti mā te Matatini III ki te kaikawe nekeneke, arā, te cytochrome c, kātahi mā te Matatini IV ki te hāora. I ia tukunga whakawhiti ka papua ngā iraoho ki tua o te kiriuhi o roto, ā, mā te rōnaki ka hua ake e akiaki te waihanga ATP. Ki te aukatia tētahi teihana, ka mutu te rere i te taha whakarunga o te rārangi.

Ka kuhu atu te kahurangi metilīni hei kaikawe whakarara. Ka kohia e tōna āhua kua whakahāoratia ngā irahiko mai i ngā kaikawe o te taha whakarunga, ā, ka huri hei āhua whakaheke, kāore nei he tae, arā, te leucomethylene blue. Kātahi ka tukuna aua irahiko ki te taha whakararo, ka hoki anō tōna tae kahurangi. E whakaahuatia ana ēnei āhua e rua i te kōrero mō te takirua pitihāora-whakaheke, ā, kei te whakamārama whānui mō te tikanga mahi te kōrero mō te āhua o taua tuku whakawhiti. Ko te pātai kāore anō kia whakatauria, kei hea te kaikawe e kuhu anō ai ki te rārangi: ki te kōhao here quinol o te Matatini III, e mōhiotia ana ko te wāhi Qo, ki te cytochrome c tonu rānei. Kei ngā āhuatanga whakamātautau te tikanga mō te putanga matua, e whakamāramatia whānuitia ana i te tātaritanga o te ara karo i te Matatini III.

Ngā mea i ine tūturu ai ngā rangahau kiore e toru

I whakamahia e ngā rangahau e toru ngā mitokōria roro kua wehea, arā, he whekauiti kua tangohia mai i te pūtau, kua whakatārewatia hoki ki tētahi wairewa ārai pH kua āta tautuhia. Kāore he pūtau tōtika, kāore he kararehe i whāngaihia ki te horopeta, kāore he tāngata i whakamātauria. E pā ana ngā kukūtanga ki te wairewa e karapoti ana i ngā whekauiti, ehara ki tētahi horopeta ā-waha mō te tangata. Ki te mau tonu taua horopaki, ka mārama te kōrero a ngā tau.

Ko te rangahau tuatahi, i ngā mitokōria roro poaka kini kua wehea, i te 100 nanomolar ki te 2 micromolar, i whakaatu i te painga me te utu i roto i te tauira kotahi. I ngā mitokōria hauora, i whakapiki te waikano i te whakamahinga hāora i te wā whakatā, engari kāore i panoni te hā i whakaongaongatia e te ADP, nō reira kāore i piki te putanga ATP kua honoa ki te hā. I te aukatitanga o te Matatini I, nā te 2 micromolar i whakahoki ake te waihanga ATP mai i te 46 ki te 93 nanomoles per minute per milligram, ina whakaritea ki te tere noa e tata ana ki te 1109. I te aukatitanga o te Matatini III, nā taua horopeta tonu i whakahoki ake te ATP mai i te takiwā o te 46 ki te 63, ina whakaritea ki te tere noa e tata ana ki te 910. I hoki mai tētahi wāhanga o te ngaohiko me te urunga konupūmā. Kāore i taea te karo i te aukatitanga cyanide o te Matatini IV, e tohu ana kei te taha whakarunga o te Matatini IV e mahi ana te putanga irahiko whai hua. He tūturu ā-tauanga ia whakaoranga mahi, engari he iti: he ōrau mati kotahi noa iho o te putanga ATP noa.

Ko te rangahau tuarua, i ngā mitokōria o te uho roro kiore i te takiwā o te 1 micromolar, i whakaū i te ara karo i te Matatini I, ā, i kitea he rohe i te Matatini III. Nā te rotenone i whakaheke te hā mai i te takiwā o te 121 ki raro iho i te 2 nanomoles of oxygen per minute per milligram, ā, nā te waikano i hiki ki te takiwā o te 21, arā, tata ki te kotahi hauono o te taumata noa, i te wā i hoki tata katoa mai ai te ngaohiko kiriuhi. Engari i muri i te aukatitanga o te Matatini III, kāore te hā, te ngaohiko rānei i hoki mai puta noa i te 1 ki te 5 micromolar, ā, nā te aukatitanga i pēhi te tohu perōkisa i hua i te waikano. I whakatakoto ngā kaituhi i te whakaaro ka tuku te waikano kua whakahekea i ōna irahiko ki te wāhi Qo o te Matatini III: ki te nohoia taua wāhi, kāore he wāhi tuku mā te kaikawe.

Ko te rangahau tuatoru, i ngā mitokōria roro o te kiore iti, te kiore nui me te poaka kini, ko te nuinga i te 2 micromolar, i whakamātau tika i taua taupatupatu, ā, i kitea ka taea te whakawhiti mā tētahi ara kē i te aukatitanga o te Matatini III. I te whakahekenga o te hā taketake e te myxothiazol, he aukati i te wāhi Qo, mā te 88 percent, nā te waikano i whakahoki ake te whakamahinga hāora ki te takiwā o te 62 percent o te tere kāore i aukatia. I tētahi whakamātautau tōtika, nā te haurua micromolar i whakaheke te cytochrome c i tāpirihia mai i waho ahakoa kua aukatia te Matatini III, e tautoko ana i tētahi ara mai i te NADH mā te waikano ki te cytochrome c, ā, haere tonu ki te Matatini IV. Engari he rerekē te whanonga o te hā i whakahokia mai: nā te ADP i tāpirihia i whakaheke te whakamahinga hāora, kāore i whakapiki, ā, nā te aukati i te waihanga ATP i whakaongaonga te hā. I hoki mai tētahi wāhanga noa o te wehenga utu hiko o te kiriuhi. Ehara te whakamahinga hāora nui me te hononga kua kōarotia i te hanga pūngao noa.

He aha ngā taiwhanga e taupatupatu ai, ā, he aha e whakatau ai

Ko te whakamārama e ahu ana i ngā rerekētanga momo kararehe te mea tuatahi kāore e tū. I tāruarua te rōpū tuatoru i te mahi ki ngā momo kiore e toru, ā, i kitea taua āhua o te ara karo i roto i a rātou katoa, tae atu ki te kāwai kiore i pūrongotia ai kāore taua ara karo i kitea. Ko ngā mea kē e rerekē ana ko te kukūtanga (1 ki te 2 micromolar), ngā horopeta aukati, ngā wairewa ārai pH, ngā tikanga wehe, ā, ko te mea nui rawa, ko te āhua pūngao e whakatauritea ana: ka tino kitea te ara karo i mua i te tāpiritanga ADP, koinei tonu te wā ka puta mai te urupare ADP tauaro. Nō reira, ka whakaatu te hoahoa pono i ngā putanga e rua e whakawhirinaki ana ki ngā āhuatanga, kotahi ki te wāhi Qo, kotahi ki te cytochrome c. Ka tuku te kaikawe ki te wāhi e whakaaetia ana e te matū o taua wāhi.

Te utu perōkisa

He rite tonu te pūmautanga o ngā kitenga mō te utu ki ngā kitenga mō te whakaora mahi. I te rangahau poaka kini, i whakapiki te waikano i te tukunga perōkisa i raro i ia āhuatanga i whakamātauria—i te whakatā, i te waihanga ATP, i te whakararunga ā-matū hoki—puta noa i ngā tïpako e toru. I te wā o te waihanga ATP, i piki te putanga mai i te takiwā o te 148 ki runga ake i te 1500 picomoles per minute per milligram i te 1 micromolar, ā, ahakoa ko te 100 nanomolar, neke atu i te whā whakarea te pikinga o te tohu. I whakapōturi hoki te waikano i te whakakorenga perōkisa mā te takiwā o te 2.6 whakarea, nō reira e whakaatu ana te tohu i te tere ake o te hanganga me te pōturi ake o te whakakorenga. Ko te tikanga matū i whakaarohia ko te whakaheke tōtika o te hāora e te waikano kua whakahekea, kāore he superoxide e kitea ana, engari he whakamāramatanga tonu tēnei, ehara i te kaupae kua whakaūngia.

Ka whakapiki te rangahau kiore i te matatini o te kōrero, engari he āwhina tōna. I tino piki te perōkisa i te pikinga o te horopeta, mai i te taumata taketake e tata ana ki te 76 ki te tata ki te 2000 picomoles per minute per milligram i te 2 micromolar, heoi nā te aukatitanga o te Matatini III i pēhi te wāhanga i hua i te waikano. Mehemea ko te tauhohenga o te waikano kua whakahekea ki te hāora anake te pūtake o te perōkisa, kāore pea te aukati i te mekameka e tino whai pānga. Engari he pānga tōna, nō reira ka whai wāhi te mekameka. Ka whakatakoto te arotake mō te ārai hāoratanga me te whakatairanga hāoratanga i tēnei āhua takirua ki tōna horopaki whānui, ā, ka whakamārama te tātaritanga hāora ki te ATP he aha e kore ai ngā tau hāora anake e whakatau i tētahi kerēme pūngao.

Ehara te whakaora mahi i te whakatika

Ko te rerenga kōrero me whakamutu te whakamahi, ko te “ka whakatika rānei te kahurangi metilīni i ngā mitokōria.” Ko te whakatika he whakatikanga toitū: he matatini kua hangaia anō, he hononga e mau tonu ana i muri i te wehenga atu o te rongoā, he hokinga mai o te mahi i ngā pūtau tōtika, kātahi he pai ake o te mahi i roto i tētahi rauropi ora. Kāore tētahi o ngā pepa e toru e whakaatu ana i tērā. E whakaatu ana rātou i te huri ara mō te wā poto i ngā whekauiti kātahi anō ka wehea, i raro i te aukatitanga matū horihori, he hautanga iti noa te putanga ATP o tōna taumata noa, ā, i ētahi wā he tino rerekē te hononga. He taputapu taiwhanga te rotenone me te antimycin, ehara i te tauira mō te koroheketanga, mō te mate mitokōria tangata rānei, ā, kāore tētahi mea i konei e tohu ana ka nui ake te pūngao o tētahi tangata hauora. He pātai taunakitanga motuhake tērā, me ōna ake tuhinga rangahau tangata.

E toru ngā rohe e noho pono ai tētahi whakatau mō te whakarerekē koiora. Tuatahi, ehara te kukūtanga o te wairewa i te horopeta: kāore te 0.1 ki te 2 micromolar e karapoti ana i ngā whekauiti kua wehea e whakaatu ana ko tēhea rahinga ā-waha ka hua ai taua kukūtanga herekore ki tētahi mitokōria roro tangata, otirā nā te mea ka whakaemi, ka tukuna rānei te waikano i runga i te ngaohiko kiriuhi tonu. Tuarua, ehara te hāora i te pūngao: ka taea e te waikano te whakapiki i te whakamahinga hāora mā te hurihuringa me te turuturu, tae atu hoki ki te tāpiritanga pūhōhā e whai hua ana. Nō reira, kāore e taea te whakamahi i te ine hā, ki te kore he pānuitanga ATP me te ngaohiko, hei tautoko i tētahi kerēme pūngao. Tuatoru, me noho te painga me te taumahatanga ki te rerenga kōrero kotahi: ko tētahi kōrero mō te ngaohiko, te ATP rānei i whakahokia mai, e mahue ai te pikinga perōkisa i puta tahi, he pūrongo hē mō te whakamātautau. Ko ētahi atu āhuatanga hei āta whakaaro, ko te taurite pitihāora-whakaheke NAD, te āhua o te urupare ki te horopeta me te aratohu whakamātautau ine.

He kupu tāpiri ā-mahi: nō taua rāpoi ngota tonu te āhuatanga kawe irahiko. He hohe pitihāora-whakaheke hoki ngā matū whanaunga kua tangohia ō rātou rōpū metilī, pērā i te Azure B, engari he rerekē te whanonga. Nō reira, he whakamātautau rerekē te wairewa kua pirau tētahi wāhanga i tō te waikano tōtika. Koinei tētahi take kia tohea te whakaritenga katoa o te pukapuka paerewa rongoā me tētahi tuhinga puranga kua whakaputaina, kaua ko te tirohanga mō ngā konganuku anake. He whakatūpato whakarara anō tō te matū e whakaongaongatia ana e te rama mō ngā whakamahinga i raro i te māramatanga, e kōrerotia ana i ngā whakakotahitanga me te rama whero.

Ka tū tonu te kerēme whāiti ahakoa ēnei mea katoa, ā, he mea tika kia puritia: ka taea e te kahurangi metilīni te mahi hei kaikawe irahiko i raro i ētahi āhuatanga i ngā mitokōria kua pakaru, kua wehea hoki, e pupuri ana i tētahi wāhanga o te rere, engari he utu perōkisa tōna. Ko ngā mea katoa kei tua atu i tērā—te pūngao, te roa o te ora, te whakatika—e tatari ana ki ngā taunakitanga kāore ēnei rangahau i hangaia hei whakarato.