Disease relevance of Cmah

• The genes for cytidine monophospho-N-acetylneuraminic acid hydroxylase (NeuAc-H) and beta-1,4-N-acetylgalactosaminyl transferase (GalNAc-T) were examined using reverse transcription-PCR in two experimental mouse brain tumors, EPEN and CT-2A [1].
• The identity of the ORF was confirmed by expression of active CMP-Neu5Ac hydroxylase in E. coli at low temperatures [2].

High impact information on Cmah

• Such Cmah repression caused activation-dependent dynamic reduction of CD22 ligand expression without losing alpha2,6-linked sialylation in germinal centers [3].
• A reconstitution experiment with the purified CMP-NeuAc hydroxylase, soluble cytochrome b5, and recombinant NADH-cytochrome b5 reductase revealed that these three factors are essential for the reaction [4].
• Purification and characterization of CMP-N-acetylneuraminic acid hydroxylase from pig submandibular glands [5].
• The sialic acid N-glycolylneuraminic acid (Neu5Gc) is synthesized by the action of CMP-Neu5Ac hydroxylase [2].
• In this paper, we present the results of an investigation into the catalytic properties of CMP-Neu5Ac hydroxylase (Neu5Ac: N-acetylneuraminic acid) in high-speed supernatants of mouse liver [6].

Anatomical context of Cmah

• Compared to the parental cell line, the new strain (CHO-AsUH2), which was transfected with a 199-bp antisense fragment derived from the mouse CMP-Neu5Ac hydroxylase cDNA, showed an 80% reduction in hydroxylase activity [7].

Associations of Cmah with chemical compounds

• In mouse germinal center B cells, the expression of the GL7 epitope was upregulated due to the in situ repression of CMP-Neu5Ac hydroxylase (Cmah), the enzyme responsible for Sia modification of Neu5Ac to Neu5Gc [3].
• An antibody against cytochrome b5 markedly reduced the CMP-NeuAc hydroxylase activity when added to incubation mixture containing either NADH or NADPH as an electron donor [8].

Other interactions of Cmah

• In summary, mTf glycans differed from those of other analyzed mammalian transferrins by the presence of Neu5Gc and by a Neu5Gc(alpha 2-6)GlcNAc linkage in trisialylated biantennary structures, reflecting in mouse liver, a high activity of CMP-Neu5Ac hydroxylase and (alpha 2-6)GlcNAc sialyltransferase [9].

Analytical, diagnostic and therapeutic context of Cmah

• Immunization of a rabbit with enriched and purified hydroxylase led to an antiserum that inhibited CMP-Neu5Ac hydroxylase activity and reacted with the purified 65 kDa protein on a Western blot after SDS-PAGE [5].
• In order to shed light on the structural basis for these differences, the primary structure of CMP-Neu5Ac hydroxylase from A. rubens has been determined by PCR and cDNA-cloning techniques, using initial sequence information from the mouse enzyme [2].
• The activity of CMP-N-acetylneuraminic acid hydroxylase, that converts CMP-N-acetylneuraminic acid (CMP-NeuAc) to CPM-N-glycolylneuraminic acid (CMP-NeuGc), in mouse liver was determined by a newly developed HPLC method using non-radioactive CMP-NeuAc as a substrate [8].

References