RENBP isomerises ManNAc, ManNGc to GlcNAc, GlcNGc

Stable Identifier
Reaction [transition]
Homo sapiens
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Humans are not able to catalyse the formation of N-glycolylneuraminic acid (Neu5Gc) due to an inactive CMAHP enzyme. Neu5Gc can be obtained from dietary sources and must be degraded to avoid accummulation and resultant chronic inflammation known as xenosialitis (Varki et al. 2011). Degradation of excess Neu5Gc results in the formation of two ubiquitous metabolites involved in asparagine N-linked glycosylation; glycolate and glucosamine 6-phosphate. In the Neu5Gc degradation pathway, N-acylglucosamine 2-epimerase (RENBP) dimer catalyses the reversible isomerisation of N-acetylmannosamine (ManNAc) to N-acetylglucosamine (GlcNAc) and of N-glycolylymannosamine (ManNGc) to N-glycolylglucosamine (GlcNGc) (Takahashi et al. 1999, 2001).

Literature References
PubMed ID Title Journal Year
21073341 Biomedical differences between human and nonhuman hominids: potential roles for uniquely human aspects of sialic acid biology

Varki, NM, Dick, EJ, Benirschke, K, Varki, A, Strobert, E

Annu Rev Pathol 2011
9990133 Human renin-binding protein is the enzyme N-acetyl-D-glucosamine 2-epimerase

Takahashi, K, Ogasawara, H, Shindo, S, Kaneko, T, Takahashi, S, Kobayashi, M

J. Biochem. 1999
11726282 Effects of nucleotides on N-acetyl-d-glucosamine 2-epimerases (renin-binding proteins): comparative biochemical studies

Takahashi, K, Hori, K, Ogasawara, H, Takahashi, S, Saito, K, Tomatsu, M

J. Biochem. 2001
Catalyst Activity

N-acylglucosamine 2-epimerase activity of RENBP dimer [cytosol]

Orthologous Events
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