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Mannosamine 6-phosphate

D-Erythrose-4-phosphate = D-Arabinose-5-phosphate = N -Acetyl-D-mannosamin-6-phosphate... [Pg.192]

This enzyme [EC 5.1.3.9], also known as A -acetylglucos-amine-6-phosphate 2-epimerase, catalyzes the interconversion of A -acylglucosamine 6-phosphate to A -acyl-mannosamine 6-phosphate. [Pg.30]

Generally, syntheses of DAHP, KDO and Neu5Ac are based on chain extension of an appropriate sugar unit electrophiles by a C3 nucleophiles, according to the biosynthetic pathway, shown in Scheme 1. Thus, the reaction of D-erythrose 4-phosphate (13) acting as a C4 electrophile with phosphoenolpyruvate (14, C3 nucleophile) creates DAHP [6]. Mutual relationship to this pathway concerns the biosynthesis of KDO and Neu5Ac, which are produced on the reaction of phosphoenolpyruvate with D-arabinose 5-phosphate (C5 electrophile) or A-acetyl-D-mannosamine 6-phosphate (C6 electrophile), respectively [5,12]. [Pg.422]

ATP + N-acyl-D-mannosamine = ADP + N-acyl-D-mannosamine 6-phosphate (acts on the acetyl and glycolyl derivatives)... [Pg.145]

A -acetyl-D-mannosamine-6-phosphate + phosphoenolpyruvate - -iV-acetyl neuraminic-9-phosphate + phosphate... [Pg.52]

Phosphoenol- N-Acetyl-D-pyruvic acid mannosamine-6-phosphate... [Pg.121]

Neuraminic acid is more complex. It is a nine-carbon amino sugar formed by the condensation of mannosamine 6-phosphate and phosphoenolpyruvate (PEP). It is the parent substance of the sialic acids which are acyl derivatives of neuraminic acid, e.g. N-acetylneuraminic acid. Sialic acids are found as constituents of glycoproteins and glycolipids and are believed to have an important bearing on the formation of the acquired integuments of the teeth (Chapter 34). [Pg.96]

A -acetyl-D-neuraminic acid is biosynthesized from A -acetyl-D-mannosamine and phosphoenol pyruvate, catalyzed by N-acetyl-D-neuraminic acid synthase. The first step involves the addition of an electron pair from the double bond of the phosphoenol pyruvate to the aldehyde group to give an aldol-type condensation (see Fig. 10.8A). The product is the nine-carbon sugar acid, A -acetyl-D-neuraminic acid [23]. In some instances the enzyme requires A-acetyl-D-mannosamine-6-phosphate as the substrate and forms A-acetyl-D-neuraminic acid-9-phosphate. Various hydroxyl groups on C-4, -7, -8, and -9 can be acetylated by specific acetyl transferases using acetyl CoAas the donor. KDO (2-keto-3-deoxy-D-mannooctulosonic acid) is biosynthesized by a very similar condensation between D-arabinose-5-phosphate and pyruvic acid, catalyzed by KDO synthase (see Fig. 10.8B) [24]. [Pg.301]

Warren, L., and Felsenfeld, H., 1961b, N-Acetyl-mannosamine-6-phosphate and N-acetylneuraminic acid-9-phosphate as intermediates in sialic acid biosynthesis, Biochem. Biophys. Res. Commun. 5 185-190. [Pg.6]

Chemical Analysis, Group A polysaccharide is a homo-polymer of D-N-acetyl-mannosamine phosphate which is partially 0-acetylated. Groups B and C are both homopolymers of sialic acid, but group C is 0- acetylated, whereas groiq) B is not. [Pg.174]

Synthetic studies for sialic acid and its modifications have extensively used the catabolic enzyme N-acetylneuraminic acid aldolase (NeuA E.C. 4.1.3.3), which catalyzes the reversible addition of pyruvate (70) to N-acetyl-D-mannosamine (ManNAc, 11) to form the parent sialic acid N-acetylneuraminic acid (NeuSNAc, 12 Scheme 2.2.5.23) [1, 2, 45]. In contrast, the N-acetylneuraminic acid synthase (NeuS E.C. 4.1.3.19) has practically been ignored, although it holds considerable synthetic potential in that the enzyme utilizes phosphoenolpyruvate (PEP, 71) as a preformed enol nucleophile from which release of inorganic phosphate during... [Pg.370]

A-Acetyl neuraminic acid aldolase [from Clostridium perfringens, A-acetylneuraminic acid pyruvate lyase] [9027-60-5] [EC 4.1.3.3]. Purified by extraction with H20, protamine pptn, (NH4)2S04 pptn, Me2CO pptn, acid treatment at pH 5.7 and pptn at pH 4.5. The equilibrium constant for pyruvate + n-acetyl-D-mannosamine ++ /V-acetylneuraminidate at 37° is 0.64. The Km for A-acetylneuraminic acid is 3.9mM in phosphate at pH 7.2 and 37°. [Comb and Roseman Methods in Enzymology 5 391 1962). The enzyme from Hogg kidney (cortex) has been purified 1700 fold by extraction with H20, protamine sulphate pptn, (NH4)2S04 pptn, heat treatment between 60-80°, a second (NH4)2S04 pptn and starch gel electrophoresis. The Km for A-acetylneuraminic acid is 1.5mM. [Brunetti et al. JBC 237 2447 1962). [Pg.460]

Similarly, condensation of D-mannosamine, as well as D-mannose with methyl dimethyl[(3-bromopropen-2-yl)phosphate] [115], instead of ethyl (bromomethyl)acrylate, led to the corresponding Neu5Ac and phosphonate analogs with much higher stereoselectivity (syn/anti 20 1). [Pg.453]

The first recorded synthesis of the phosphonate analogue (251) of iV-acetyl-a-D-mannosamine 1-phosphate commences with the Arbuzov conversion of (248) into (249), and thence into (250) by aqueous trifluoroacetolysis. Standard reactions carried out on the last yield the target compound. ... [Pg.139]

Mannosamine, A-312 Mannosan, A-675 D-Mannosazone, H-90 L-Mannosazone, H-90 Mannose 6-dihydrogen phosphate, M-115 Mannose dimethyl dithioacetal, M-116 Mannose 1,2-orthoacetate, M-117 D-Mannose phenylosotriazole, H-90 L-Mannose phenylosotriazole, H-90 Mannose 6-phosphate, M-115 Mannose, M-114... [Pg.1069]

Of significance are D-glucosamine and D-mannosamine (Fig. 29). d-G1ucos-amine-6-phosphate is formed from fructose-6-phosphate by the pathway given in Fig. 32. It is subsequently transformed to iV-acetylglucosamine-6-phosphate and iV-acetylmuramic acid. Synthesis of D-glucosamine-6-phosphate includes an intramolecular oxidoreduction at positions 1 and 2 transforming the ketose to an aldose derivative. [Pg.120]

Another liver enzyme uses N-acetylglucosamine-6-phosphate as a substrate to yield N-acetylmannosa-mine-6-phosphate. An enzyme obtained from hog kidney converts free N-acetylglucosamine to N-acetyl-mannosamine. An N-acetylmannosamine kinase requiring magnesium and potassium for activity phos-phorylates N-acetylmannosamine to yield the N-ace-tylmannosamine-6-phosphate. ATP acts as phosphate donor. [Pg.187]

Heyns and Koch succeeded [96] in confirming the structure of the rearrangement product from the reaction of D-fructose and ammonium chloride in the presence of phosphate and proposed a mechanism (Scheme 28). They pointed out that both epimers at position C-2, D-glucosamine (4) and D-mannosamine (5), were formed with the thermodynamically more stable compound 4 preponderating and recognized that this reaction is related to the Lobry de Bruyn -... [Pg.137]


See other pages where Mannosamine 6-phosphate is mentioned: [Pg.7]    [Pg.136]    [Pg.145]    [Pg.145]    [Pg.26]    [Pg.121]    [Pg.361]    [Pg.4]    [Pg.507]    [Pg.127]    [Pg.31]    [Pg.81]    [Pg.460]    [Pg.87]    [Pg.81]    [Pg.121]    [Pg.382]    [Pg.255]    [Pg.31]    [Pg.121]    [Pg.864]    [Pg.1583]    [Pg.507]    [Pg.214]    [Pg.7]    [Pg.500]    [Pg.671]    [Pg.136]    [Pg.145]    [Pg.145]    [Pg.145]    [Pg.194]    [Pg.798]    [Pg.26]    [Pg.121]    [Pg.107]    [Pg.286]    [Pg.286]    [Pg.217]   
See also in sourсe #XX -- [ Pg.96 ]




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