Glycyl-tryptophan

Glycyl glutamic acid Glycyl proline Glycyl tryptophan Leucyl glycyl phenylalanine Tryptophanyl alanine Tryptophanyl glycine Tryptophanyl tryptophan Tryptophanyl tyrosine... 

Phenylalanine pH 2.0 Phenylalanine pH 12.0 Tyrosine pH 6.0 Tryptophan pH 2.0 Tryptophan pH12.0 Tyrosyl glycine Glycyl tyrosine Leucyl tyrosine Tyrosyl tyrosine Tyrosine anhydride Tryptophan ethyl ester Glycyl tryptophan pH 2,0... 

Firstly, it is evident that the free aromatic amino acids are not the correct standards from which to determine the contributions to protein absorption. The same can be said of peptides of the aromatic amino acids. Although peptide combination causes some shift in the spectra of the aromatic amino acids it is not sufficient to account for the shift occurring in proteins (Section VI, 2). However it may be an improvement to use the peptides for comparison rather than the free amino acids, for Edwards (1949) found a much better fit to gramicidin curves by using glycyl-tryptophan as a standard. A drawback to the use of peptides is that they are more difficult to purify than the amino acids and some are difficult to synthesize. One should ideally employ a sandwich tripeptide with the aromatic acid in the middle, but no reports of the synthesis of such peptides have come to the authors notice. Secondly, if it were possible to measure precisely the shift in the spectra it should be possible to allow for this in the calculations. For instance if the shift were estimated as AX it would be possible to measure the absorption of the protein at Xi - - AX and Xz -h AX or alternatively to measure the amino acids at Xi — AX and Xj — AX and the protein at Xi and X2. 

Reaction of aldehydes with the indole NH group of tryptophan in proteins has been reported in tetanus toxin (251) and tobacco mosaic virus (26). In the latter instance, the Folin s phenol reagent color value decreased as the reaction with formaldehyde proceeded, and increased with removal of the aldehyde by dialysis in dilute acid. Indole, pure tryptophan, and glycyl tryptophan behaved in a similar manner, but not t3unsine nor glycyltyrosine. Benzaldehyde, acetaldehyde, propionalde-hyde, and butyraldehyde were also used in this work with similar effect. Reversal of formaldehyde inactivation of tobacco mosuc virus could not be confirmed (356). It was also claipaed that the drop in phenol color could not be correlated with a decrease in virus infectivity. 

The original application of the method to proteins was based on the assumption that the absorption of amino acids is unaffected when they are linked in a polypeptide chain. Later work has suggested that in preparing the standard solutions the use of amino acids in peptide combination is more satisfactory, e.g., glycyl-tryptophan (106), since a red shift (1 to 3 nm) in the absorption maximum of a free amino acid occurs when it is incorporated in proteins. Bencze and Schmidt (39) modified the procedure of Goodwin and Morton (150) in order to overcome this problem. 

Fig. 12. Difference spectra of the individual aromatic amino acid residues (Pig. 12a) and of three proteins (Fig. 12b) solution of pH 6 to 7 in sample beam and solution of pH 1 to 1.5 in reference beam. Curve 1 10 M glycyl-n-phenylalanine curve 2.5 X 10 M glycyl-L-tyrosine and curve S 5 X 10 M glycyl-L-tryptophan. (Yanari and Bovey, 1960.)...

Die Prafixe werden in alien Derivaten vor den Nainen der Aminosaure gesetzt (z. B. Acetyl-L-tryptophan, 4-Oxy-L-prolin, Glycyl-DL-leucin, jedoch nicht Phenyl-L-alanin, sondern nach wie vor L-Phenylalanin). 

Stability constants of mixed ligand complexes containing ATP, tryptophan (Trp) and copper(ii) have been obtained. The reaction of amines with [Cu(Bz-AlaO)2],-H2O (Bz-AlaO = A -benzoyl-DL-alaninato) gives adducts [Cu(Bz-AlaO)2],B (n = 1, B = piperazine, 3-Me-py, 4-Me-py, 2,2 -bipy, 4,4 -bipy, or phen n = 2, B = piperidine or morpholine). The crystal structure of aqua(glycyl)-L-tryptophanatocopper... 

A number of new copper complexes have also been found to have antiinflammatory activity. Copper(II)(j8-oxo-2-thiophenepropionitrile) is effective in treating rat polyarthritis [175]. The copper complex of glycyl-L-histidyl-L-lysine, Cu(II)(GHL), is claimed to have anti-inflammatory activity and increase the rate of wound healing [176, 177] consistent with earlier reports of increased gastric wound healing rates associated with Cu(II)(aspirinate)4 and Cu(II)(tryptophanate)2 treatment [178]. Copper(II)(L-histidinate)2, Cu(II)-... 

Optically Active. Glycyl-l-tyrosine. Glycyl-d-alanine. Glycyl-d-tryptophane. Glycyl-l-phenylalanine. Glycyl-3, 5-diiodo-l-tyrosine. dl-Alanyl-d-alanine. 1-AlanyI-glycine. d-Alanyl-d-alanine. d-AIanyl-l-leucine. d-Alanyl-d-tryptophane. 

Figure 7.11 Chromatograms of a mixture of amino acids and peptides eluted with 0.02 M SDS mobile phases containing (a) 3% 2-propanol, (b) 12.5% acetonitrile, and (c) 3% tetrahydrofuran. Compounds (1) tyrosine, (2) methionine, (3) alanyi-tyrosine, (4) tryptophan, (5) aspartyl-phenylalanine, (6) leucyl-tyrosine, and (7) glycyl-leucyl-tyrosine. Reprinted from Ref 10 with permission of Elsevier.

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