L-Alanylglycine

FIGURE 27 6 Structural features of the dipeptide l alanylglycine as determined by X ray crystallography... 

Several other organic and inorganic reaction intermediates have been studied using NMR methods. Trahanovsky et al. [12] reported a series of experiments in which they studied unstable molecules, such as benzocyclobutadiene, using flow NMR. Tan and Cocivera [13, 14] studied the reaction of 4-formylpyridine with amino acids, imidazole and D,L-alanylglycine using stopped-flow proton NMR. 

L-alanyl-L-alanine methyl ester L-alanylglycine ethyl ester... 

L-alanylglycyl-L-cysteinyl-L-lysyl-L-asparaginyl-L-phenylalanyl-L-phenylalanyl-L-tryptophanyl-L-lysyl-L-threonyl-L-threonyl-L-cysteine 6-0-benzoyl-N-(benzyloxycarbonyl) methylamide 4,6-0-benzylidene-N-benzylidene-N-(benzyloxycarbonyl) methylamide N- (benzyloxy carbonyl) -N-(benzyloxycarbonyl)-, amide N-(benzyloxycarbonyl)-, hydrazide N-(benzyloxycarbonyl)-, methylamide N-(benzyloxycarbonyl)-, methyl ester N-(benzyloxycarbonyl)-L-alanyl-L-alanine methyl ester N-(benzyloxycarbonyl)-L-alanylglycine ethyl ester N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 3,4,6-tri-0-acetyl-2-amino-2-deoxy-N-(benzyloxycarbonyl)-, benzyl ester, hydrochloride... 

The VCD spectra of glycyl-L-alanine and L-alanylglycine (83, 93) (Figure 16) are in striking contrast to one another. The strong positive methine VCD... 

Mitani and Inoue (49) found that the inhibition of mycelial growth of P. sasakii by polyoxins was protected by glycyl-L-alanine, glycyl-D,L-valine and D,L-alanylglycine. Therefore, the peptides may act as antagonists to the incorporation of polyoxins into the cell of the fungus. 

Several monodisperse model proteins with repeating sequences of amino acids have been biosynthesized by the recombinant DNA technique and have had their structure studied.86 Multigram quantities were produced in pilot fermentators. Thus, poly(L-alanylglycine), poly (AG), with alternating alanyl and glicyl units, was prepared with two different chain lengths (AG)64 and (AG)24o-87 Structural studies were... 

L-Leucyl-L-alanylglycine-L-valine, 517 L-Leucyl-L-methionine amide, 745 Levopimaric acid, 37 Levulinic add, 564-566 Lichen depsides, 232 Liebemiann-Butchard test, 1118 Limonene, 567, 646, 749-75Q, 922,1020 Linalool, 499 Linalool (R and S), 809 Lindlar catalyst, 566-567,1277 Unoleic add, 818, 1008, 1052, 1155, 1264, 1265, 1286 isomers, 260... 

The excellent agreement obtained for )5-PLA would indicate that this force field should be transferable to other APRS polypeptides, of course taking due accoimt of side-chain differences. This has been done for Ca-poly(L-glutamate), Ca-PLG [92], which X-ray and electron diffraction data had indicated to have an APPS structure but which were not extensive enough to provide a definitive conclusion. A proposed model [93] was used as the basis for the vibrational analysis, and the good prediction of the observed bands [92] supports both the model as well as the viability of the force field. The subtle differences between the -PLA and fi-Ca-PVG spectra are accounted for by the normal mode calculation, and emphasize the influence of the side chain on the main-chain modes, particularly on amide III. A similar successful vibrational analysis has been done on an alternating copolymer, APPS poly(L-alanylglycine) [19]. 

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