CYANOCOBALAMIN (VITAMIN B12)
Imiterere n'Imiterere
Iki gicuruzwa ni ifu y'umutuku wijimye cyangwa iy'amabara atukura, nta mpumuro, nta buryohe kandi gifite ubushobozi bukomeye bwo gukurura ubushuhe. Gishonga gato mu mazi cyangwa muri ethanol, ntigishonga muri chloroform cyangwa ether. Kirwanya ubushyuhe, ariko gishobora kutagira umumaro iyo gihuye n'ibintu bigabanya ogisijeni cyangwa bigabanya (nka vitamine C cyangwa hydrogen peroxide, nibindi), umunyu mwinshi w'ibyuma n'aside ikomeye na alkali zikomeye.
Imiterere y'Ubutabire
Vitamine B12 ni imvange y’ikirahure irimo iyoni za kobalti. Imiterere yayo yo hagati ni impeta y’urutare igizwe na pyrroles enye zihujwe. Molekile za vitamine B12 zigizwe n’ibice 3: impeta ya gourin chylated na atomi enye za N na iyoni za kobalti zo hagati; 5,6-dimethylbenzimidazole (5,6-dimethylbenzimidazole, DMBI) ihujwe na atomi za N-7 na iyoni za kobalti nk’utunyangingo twa vitamine B 12 tw’utunyangingo duto (α). Byongeye kandi, DMBI ihujwe na aminopropanol binyuze mu matsinda ya fosfeti, kandi aminopropanol ihujwe n’uruhererekane rw’aside propionic kuri pyrrole D; itsinda rya adenosyl cyangwa itsinda rya methyl. Ihujwe na iyoni za kobalti kugira ngo ikore ligand yo hejuru (β) ya molekile za vitamine B12. Ubwoko butandukanye bw’ibintu bya vitamine B12 bukorwa iyo itsinda ry’igitabo cy’imiti ritandukanye n’igitabo cy’imiti cyo hejuru ku murongo w’impeta ya goline. Itsinda rya hydroxyl (-OH) rihujwe na iyoni ya cobalt iri mu ruziga rwa gluline kugira ngo rikore hydroxycobalamin. Mu buryo nk'ubwo, deoxyadenosine (5'-deoxyadenosyl), methyl (-CH3), cyanide (-CN) na iyoni za cobalt bihujwe kugira ngo bikore adenosine cobalt uko bikurikirana. Amine (deoxyadenosylcobalamin), methylcobalamin (methylcobalamin) na cyanocobalamin (cyanocobalamin). Mu miterere, ubwoko bwa nyuma bwa vitamine B12 ikorwa na mikorobe ni adenosine cobalamine (coenzyme B12), methyl cobalamine na hydroxycobalamine. Ariko, kubera ko imiterere yabyo idahamye cyane, sodium cyanide yongerwamo mu buryo bw'ubukorano mu nzira yo gusukura imiterere karemano ya vitamine B12 ikaba cyanocobalamin ihamye kurushaho.
Imikorere y'umubiri
Kongera ikoreshwa rya aside folike, gukora meththionine (ikomoka kuri cysteineine nyinshi) na choline hamwe na aside folike, no gukora cyanocobalamin ibanziriza nka methyl cobalamin na coenzyme B12 mu gukora prine na pyrimidine, kandi ugire uruhare mu mikorere ya methylation y'ibintu byinshi by'ingenzi. Iyo vitamine B12 ibuze, imikorere yo kwimura amatsinda ya methyl kuva kuri aside methyl tetrahydrofolic iragabanuka, bigatuma aside folike iba idafite akamaro, bigatuma aside folike ibura. Gukomeza imikorere n'imikorere ya myelin sheath y'imitsi. Kubura vitamine B12 bishobora gutera indwara z'imitsi, kwangirika k'umugongo, no gukoresha imiti bishobora gutera ibimenyetso bikomeye byo mu mutwe. Kubura vitamine B12 bishobora gutera indwara z'imitsi yo mu gice cy'imbere cy'umubiri. Ibimenyetso bya mbere by'ibura rya vitamine B12 mu bana ni ukwiyumva nabi, kudakora neza, gukora buhoro, amaherezo bigatera kubura amaraso. Guteza imbere iterambere n'ubukure bw'uturemangingo dutukura tw'amaraso. Methylpropandiyl coenzyme A ihinduka succinoyl coenzyme A kandi igira uruhare mu mikorere ya aside tricarboxylic, aho succinyl coenzyme A ifitanye isano no gukora heme. Vitamine B12 igira uruhare kandi mu gukora aside deoxynucleic (DNA), mu gutunganya ibinure, karubohidrati na poroteyine, kandi yongera gukora aside nucleic na poroteyine.
