Glycyl-L-alanine

Elongation of the peptide chain in the direction of the N-terminal by a solid-phase procedure was introduced by Lavielle and coworkers,132 who prepared the glycopeptide [3-0-(2-acetamido-2-deoxy-/ -D-gluco-pyranosyl)-L-serine]-L-glycyl-L-alanine (189) by first coupling 168, de-protected by hydrogenolysis, to an L-alanyl resin (188), and, after re-... 

N-(terf-butoxycarbonyl)-N-(tert-butoxycarbonyl)-, benzyl ester glycyl-L-alanine-, methyl 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... 

Fig. 10. Conformational map of glycyl-L-alanine. The locations of the right- and left-handed a-helices are denoted by an, and ccl, respectively. The fully-stretched chain is located at the origin. The full and dashed lines represent the boundaries of sterioally allowed regions for this dipeptide, as calculated by Ramachandran et al. (1963a) with two different sets of assumptions about van der Waals contact distances.

Fio. 20. Contour diagram of total potential energy of glycyl-L-alanine at 1 kcal mole-1 intervals (for D=3-5). On the basis of this potential surface o/nj>Z)f = 9-13 (Brant and Flory, 1965c). 

Venkatachalam and Ramachandran (1967) have evaluated the various nonbonded potential functions described in Section VB, by using them to calculate nonbonded potential energy contours for the dipeptide glycyl-L-alanine and for helical poly-L-alanine. The functions considered were those of Brant and Flory (1965c), De Santis et al. (1965), Scott and... 

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. 

One of the immediate successes of the PCILO method when applied to the simple model dipeptides, say, glycyl-L-alanine, was to predict the most stable form of such a compound, a conformation which completely escaped the attention of the great majority of the previous empirical computations and also of the EHT calculations. This conformation is represented by a seven-membered hydrogen-bonded ring (Fig. 28). As the next most stable conforma-... 

Fig. II, Allowed areas of the steric map for various dipeptides. In area 0 no conformations are allowed. Conformations in areas 1 to 4 are allowed for glycyl glycine, in areas 2 to 4 for glycyl-L-alanine, in areas 3 to 4 for higher straight-chain homologs, while only area 4 is allowed for glyeyl-L-valine and glycyl -n -isoleucine. The circles marked R and L indicate the location of the standard right- and left-handed a-helix on the steric map (Nemethy etal., 1900a,b).

Zeeman-perturbed NQR was applied by Kehrer et al. to determine the EFG tensor in glycyl-L-alanine hydroiodide monohydrate. Although this is not a typical solid-state NMR study, it is interesting to quote the quadrupolar parameters, Cq( I) = 74.04 MHz and rjQ = 0.776 (at 274.5 K) since the corresponding hydrobromide salt is isomorphous and could be of interest for further study. 

N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 145-146 -26.6 HCONMe. 131... 

A misleading statement that ATR of water solutions requires concentrations of 20 % or higher was made in the review by Pawlak et al. (quoting a paper by Katlafsky and Keller, 1963). Parker (1963) has shown that suitable ATR spectra can be obtained on 5 % solutions of glycyl-L-alanine, and evidence points to the detection of other substances at concentrations much less than 20 % (Hermann, 19656). 

---