Cobalamin (Cbl, vitamin B12) transport and metabolism

Banerjee R, Gouda H, Pillay S. Redox-Linked Coordination Chemistry Directs Vitamin B12 Trafficking. Acc. Chem. Res. 2021 Apr 02;54(8):2003–13. doi: 10.1021/acs.accounts.1c00083.; Nielsen MJ, Rasmussen MR, Andersen CB, Nexø E, Moestrup SK. Vitamin B12 transport from food to the body's cells--a sophisticated, multistep pathway. Nat Rev Gastroenterol Hepatol. 2012 May 01;9(6):345–54. doi: 10.1038/nrgastro.2012.76. PMID: 22547309.; Froese DS, Gravel RA. Genetic disorders of vitamin B12metabolism: eight complementation groups – eight genes. Expert Rev. Mol. Med. 2010 Nov;12(). doi: 10.1017/s1462399410001651.; Green R. Ins and outs of cellular cobalamin transport. Blood. 2010 Feb 25;115(8):1476–7. doi: 10.1182/blood-2009-12-254037. PMID: 20185591.; Quadros EV. Advances in the understanding of cobalamin assimilation and metabolism. Br J Haematol. 2009 Dec 17;148(2):195–204. doi: 10.1111/j.1365-2141.2009.07937.x.; Seetharam B. RECEPTOR-MEDIATED ENDOCYTOSIS OF COBALAMIN (VITAMIN B12). Annu. Rev. Nutr. 1999 Jul;19(1):173–95. doi: 10.1146/annurev.nutr.19.1.173.

Metabolites

H+

Formula: H (1.0078246)

CAS ID: 12408-02-5

H2O

Formula: H2O (18.0105642)

CAS ID: 7732-18-5

Hydrogen cyanide

Formula: CHN (27.010898599999997)

CAS ID: 74-90-8

Zinc cation

Formula: Zn (63.929145)

CAS ID: 23713-49-7

Adenosylcobalamin

Formula: C72H101CoN18O17P (1579.6661325999999)

CAS ID:

NADPH(4-)

Formula: C21H26N7O17P3 (741.0598016)

CAS ID: 53-57-6

ATP(4-)

Formula: C10H12N5O13P3 (502.9644492)

CAS ID:

NADH(2-)

Formula: C21H27N7O14P2 (663.1091182000001)

CAS ID:

NAD(1-)

Formula: C21H26N7O14P2 (662.1012936000001)

CAS ID: 53-84-9

ADP(3-)

Formula: C10H12N5O10P2 (424.0059412)

CAS ID:

NADP(3-)

Formula: C21H25N7O17P3 (740.051977)

CAS ID: 53-59-8



Enzyme

EC Number name full name note
2.5.1.-
1.16.1.6 cyanocobalamin reductase cob(II)alamin, hydrogen cyanide:NADP+ oxidoreductase
1.16.1.8 [methionine synthase] reductase [methionine synthase]-methylcob(III)alamin,S-adenosyl-L-homocysteine:NADP+ oxidoreductase
2.1.1.13 methionine synthase 5-methyltetrahydrofolate:L-homocysteine S-methyltransferase
2.5.1.151 alkylcobalamin dealkylase methylcobalamin:glutathione S-methyltransferase
5.4.99.2 methylmalonyl-CoA mutase (R)-methylmalonyl-CoA CoA-carbonylmutase
7.6.2.2 ABC-type xenobiotic transporter ATP phosphohydrolase (ABC-type, xenobiotic-exporting)
7.6.2.3 ABC-type glutathione-S-conjugate transporter ATP + H2O + glutathione-S-conjugate[side 1] = ADP + phosphate + glutathione-S-conjugate[side 2]
7.6.2.8 ABC-type vitamin B12 transporter ATP phosphohydrolase (ABC-type, vitamin B12-importing)


Proteins

Protein ID name full name