Glycine aspartate glutamine

The extension to amino acid synthesis on surfaces has also been observed with platinised Ti()2 surfaces, with CH4, NH3 and H20 solutions producing glycine, alanine, glutamine, aspartic acid and serine, all photosynthesised and trapped in the resulting layers near to the surface by their charge. 

The amino acids glycine, aspartate, and glutamine are used in purine synthesis. 

The atoms of the purine ring are contributed by a number of compounds, including amino acids (aspartic acid, glycine, and glutamine), CO2, and N10-formyltetrahydrofolate (Figure 22.5). The purine ring is constructed by a series of reactions that add the donated carbons and nitrogens to a preformed ribose 5-phosphate. (See p. 145 for a discussion of ribose 5-phosphate synthesis by the HMP pathway.)... 

Fig. 2. BEO significantly reduces excitatory amino add (Asp and Glu) efflux in the frontoparietal cortex typically observed following MCAo. Effect of BEO (B solid line) or vehicle (V dotted line) administration (B/V, 0.5 ml/kg, i.p., 1 h before MCAo) on dialysate levels of glutamate, aspartate, glutamine, glycine, citrulline, taurine, and GABA detected in the upper frontoparietal cortex following pMCAo. Data are mean S.E.M. (n = 3 per group) P < 0.05, P < 0.01, P < 0.001 versus vehide, Student s Mest.

Higher eukaryotic cells have lost the ability to synthesize a number of amino acids. These amino acids are generally called essential amino acids, while those that can be synthesized are called non-essential. However, this nomenclature is very misleading for two reasons. First, some of the non-essential amino acids are in fact very essential in that they are required for synthesis of nucleotides (glycine, aspartate, and glutamine). The reason why the ability to synthesize these amino acids has been retained may well be that they are indispensable. Secondly, the capability to synthesize them... 

Purine nucleotides can be synthesized in the organism from relatively simple building blocks ribose, phosphate, glycine, formate, aspartate, glutamine, and C02. The origin of each purine base component is summarized in Figure 10.5,... 

Purine nucleotides can be produced by two different pathways. The salvage pathway utilizes free purine bases and converts them to their respective ribonucleotides by appropriate phosphoribosyltransferases. The de novo pathway utilizes glutamine, glycine, aspartate, N -formyl FH4, bicarbonate, and PRPP in the synthesis of inosinic acid (IMP), which is then converted to AMP and GMP. 

The purine ring is assembled from a variety of precursors glutamine, glycine, aspartate, N formyltetrahydrofolate, and (XT. The committed step in the de novo synthesis of purine nucleotides is the formation of 5-phosphoribosyIamine from PRPP and glutamine. The purine ring is assembled on ribose phosphate, in contrast with the de novo synthesis of pyrimidine nucleotides. The addition of glycine,... 

Different amino acids favor the formation of alpha helices, beta pleated sheets, or loops. The primary sequences and secondary structures are known for over 1,000 different proteins. Correlation of these sequences and structures revealed that some amino acids are found more often in alpha helices, beta sheets, or neither. Helix formers include alanine, cysteine, leucine, methionine, glutamic acid, glutamine, histidine, and lysine. Beta formers include valine, isoleucine, phenylalanine, tyrosine, tryptophan, and threonine. Serine, glycine, aspartic acid, asparagine, and proline are found most often in turns. 

In the biosynthesis of nucleosides, ribose combines with an intermediate from the initial stage of purine ring construction. It was found that the base portion was constructed from glycine and glutamine, and that a nitrogen atom originated from aspartic acid, and of the two Cj units one is derived from carbon dioxide and the other from a molecule of formic acid. 

On the basis of whole-animal nutritional studies, 14 amino acids are conventionally considered as essential for cultured cells arginine, cysteine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, tyrosine, and valine. Conversely, the naturally occurring nonessential amino acids include alanine, serine, asparagine, proline, glycine, aspartic acid, and glutamic acid. Nutritional requirements for amino acids vary, both quantitatively and qualitatively, with cell type, culture condition, and genetic modification. 

Adapted from Wu (2009). AGGS, aspartate, glutamine, glycine and serine BCAA, branched-chain amino acids BET, betaine CHO, choline CO, carbon monoxide DOP, dopamine EPN, epinephrine and nor epinephrine GlcN-6P, glucosamine-6-phosphate MEL, melanin MLT, melatonin MH, 3-methylhistidine NO, nitric oxide SAM, S-adenosylmethionine STN, serotonin, UCA, urocanic acid. 

It is a peptide containing 27 amino acid residues containing the amino acids L-histidine (His) L-aspartic acid (Asp) L-serine (Ser) glycine (Gly) L-threonine (Thr) L-phenyl-alanine (Phe) L-glutamic acid (Glu) L-glutamine [Glu(NHj)] L-leucine (Leu) L-arginine (Arg) L-alanine (Ala) and L-valinamide (Va -NHj). 

Since biosynthesis of IMP consumes glycine, glutamine, tetrahydrofolate derivatives, aspartate, and ATP, it is advantageous to regulate purine biosynthesis. The major determinant of the rate of de novo purine nucleotide biosynthesis is the concentration of PRPP, whose pool size depends on its rates of synthesis, utilization, and degradation. The rate of PRPP synthesis depends on the availabihty of ribose 5-phosphate and on the activity of PRPP synthase, an enzyme sensitive to feedback inhibition by AMP, ADP, GMP, and GDP. 

Figure 4.4 Release of amino acids from cortical slices exposed to 50 mM K+. Measurements by HPEC and fluorescence detection after reaction of amino acids with o-phthalaldehyde 1, aspartate 2, glutamate 3, asparagine 4, serine 5, glutamine 6, histidine 7, homoserine (internal standard) 8, glycine 9, threonine 10, arginine 11, taurine 12, alanine 13, GABA 14, tyrosine. Glutamate concentration is almost 1 pmol/gl which represents a release rate of 30 pmol/min/mg tissue...

Included amino acids were alanine, arginine, aspartic acid, asparagine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threanine, tryptophan, tyrosine, and valine. 

The interaction with both synthetic and naturally occurring amino acids has been studied extensively glycine (138, 173, 219-221), a-(173, 219) and /3-alanine (138, 220), sarcosine (219), serine (222), aspartic acid (138, 173, 222-226), asparagine (222), threonine (222), proline (219), hydroxyproline (219), glutamic acid (138, 222-225), glutamine (222), valine (219, 227), norvaline (219), methionine (222, 226), histidine (228, 229), isoleucine (219), leucine (219, 230), norleu-cine (219), lysine (222), arginine (222), histidine methyl ester (228), phenylalanine (138, 222), tyrosine (222), 2-amino-3-(3,4-dihydroxy-phenyl jpropanoic acid (DOPA) (222), tryptophan (222), aminoiso-butyric acid (219), 2-aminobutyric acid (219,231), citrulline (222), and ornithine (222). 

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