Valine 692 / INDEX

Figure 2 shows an alignment of 104 of the known 5-HT receptors from vertebrates, for clarity, sequences for which the databases contain incomplete or incorrect sequences (see above) have been omitted. In TM1, the index residue N1.50 is completely conserved among all 104 receptors position 1.53 is a valine in all but the 5-HT6 receptors, in which it is a leucine. In helix 2, residue D2.50 is completely conserved among all 104 receptors, as are S2.45 and V2.57. In TM3, the DRY motif is conserved in all but one of the receptors, the exception being one of the two 5-HT7-like receptors from the pufferfish... 

As discussed in Section 10.8.2, moderate vitamin B12 deficiency results in increased accumulation of methylmalonyl CoA, and methylmalonic aciduria and methylmalonic acidemia. This can be exploited as both a means of detecting subclinical deficiency and monitoring vitamin B12 status in patients with pernicious anemia who have been treated with parenteral vitamin. As they become depleted, the excretion of methylmalonic acid, especially after a loading dose of valine, will provide a sensitive index of depletion of vitamin Bi2 reserves. 

Methylmalonyl CoA mutase is especially sensitive to vitamin B12 depletion, so methylmalonic aciduria is the most sensitive index of vitamin B12 status. Folate deficiency does not cause methylmalonic aciduria. However, up to 25% of patients with confirmed pernicious anemia excrete normal amounts of methylmalonic acid, even after a loading dose of valine (Chanarin et al., 1973). 

Figure 9.7 Plots of log QH index vs. log Po of Rj substituent for amino acid OPA-NAC derivatives, eluted with 0.05 M SDS micellar mobile phase at pH 3 containing (a) 5% methanol, (b) 3% 1-propanol, and (c) 1% 1-pentanol. Amino acids alanine, asparagine, aspartic acid, glutamic acid, glutamine, isoleucine, leucine, phenylalanine, serine, threonine, tryptophan, tyrosine, and valine. Reprinted from Ref 20 with permission of Vieweg Publishing.

L-valine, L-proline, L-leucine, and L-phenylalanine as initiators of the ROP of DTC and TMC. PTMC and poly(dimethyl trimethylene carbonate) (PDTC) with different Mn were obtained at 80 and 120 °C, respectively, in bulk by changing the molar ratio of [monomer]/[amino acid]. Among these polymers, the maximum values of A n of the PCs reached 17 800-18 900 and the dispersity index was 1.67 for [monomer]/[r-phenylalanine] molar ratio of 200. NMR spectroscopic analysis demonstrated that amino acid was incorporated into the polymer chain. 

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