Lysine-Tyrosine

The amounts of single amino acids excreted in urine in the conjugated form, as determined independently by Stein and Muting, are given in Tables 1 and 2. According to Stein, glycine, glutamic acid, aspartic acid, histidine, and proline are quantitatively the most important amino acids liberated in the course of urine hydrolysis. Serine, lysine, tyrosine, cysteine and cystine, threonine, alanine, valine, phenylalanine, and leucine are... 

Clearly, the potential to use spin labels as a means to reduce protein concentration for detection of protein-ligand interactions, given by the factor of 6582, is tremendous. The sixth-power dependence on electron-proton distance underlines the need to carefully design the residue type which is to be spin labeled. Residues that can be spin labeled include lysine, tyrosine, cysteine, histidine, and methionine [7, 14]. At least one residue of... 

Dolichos lablab L. Bai Ben Dou (Hyacinth bean) (flower, seed) Glucokinin, plant insulin, tryptophane, arginine, lysine, tyrosine.62 Treat menorrhagia, leucorrhea, metritis. 

Glutamic acid, Lysine, Tyrosine Escherichia coli, Bacillus subtilus, Aeromonas phenologenes, Porcine kidney mitochondria, Sugar beet 74, 75,76,77, 78,79... 

Copolymer is prepared by copolymerization of the N-carboxyanhydrides of tyrosine, alanine, lysine, and glutamic acid. The polymerisation was carried out at ambient temperature in anhydrous dioxane with diethylamine as initiator. Glatiramer Acetate have the ratio alanin glutamic acid lysine tyrosine = 1 6 4.54 2. 

Another problem was the number of chelating groups attached to each protein. Diazonium reagents react with many different amino acid side chains including those of lysine, tyrosine, and histidine (24). There-... 

The molar ratios of most of the amino acids in the protein of the German cockroach are generally similar to those of vertebrates and other invertebrates with respect to whole animal protein hydrolyzates (1). However, histidine, lysine, tyrosine, leucine, isoleucine, valine, and alanine are somewhat more abundant in cockroach protein and there is less cystine. The data vary significantly from data previously reported on the amino acid composition of the German cockroach (7). The earlier analysis, however, was conducted on insects with the entire head and digestive tract removed and the remaining portions of the body extracted with lipide solvents only. 

Acid-base catalysis does not contribute to rate enhancement by a factor greater than —100, but together with other mechanisms that operate in the active site of an enzyme, it contributes considerably to increasing the enzymatic rate of reactions. The amino acid side chains of glutamic acid, histidine, aspartic acid, lysine, tyrosine, and cysteine in their protonated forms can act as acid catalysts and in their unprotonated forms as base catalysts (see Prob. 8.11). Clearly, the effectiveness of the side chain as a catalyst will depend on the p/ffl (Chap. 3) in the environment of the active site and on the pH at which the enzyme operates. 

Leucine 2,3-aminomutase interconverts the a and /3 forms of leucine. Similar mutases are known for other amino acids including lysine, tyrosine, and serine. The resolving power of HPLC is useful in separating and quantitating the a and /3 derivatives of these amino acids. 

It is interesting to note that aspartic acid and/or asparagine and glutamic acid and/or glutamine form part of the peptides of all the wine fractions of different studies, independently of the type of wine or the analytical methodology employed in the analysis. Serine, threonine, alanine and glycine appear in most of the fractions studied while, lysine, tyrosine, valine, leucine, histidine and isoleucine has been found in a minor extent in these fractions. 

Horner (1954) constructed a theoretical curve for the titration of wool with alkali using amino acid analyses and the pKa values obtained for the side-chain groups of lysine, tyrosine, and arginine in the form of the free acids. He obtained a better fit using the Donnan expression of Peters and Speakman (1949) than he did with the Gilbert-Rideal (1944) expression. Obviously, much depends on the pKa values used hydrogen bonding in a protein structure can shift these values by more than one pH unit. Also, the assumption was made that the affinity of sodium ions for the... 

Reactive properties of aryl diazonium salts Aryl diazonium cations are electrophilic reagents and appear to react predominantly with four types of amino acids - lysine, tyrosine, histidine and cysteine. Although the precise structure of the cysteine derivatives is unclear, aryl diazonium salts can react with lysine, histidine and tyrosine as indicated in eq. (5.3) below to give the various substituted derivatives. 

The monazo and bisazo derivatives of lysine, tyrosine, and histidine are unstable to acid hydrolysis and the native amino acids are not regenerated. Therefore, the best method to quantitate the extent of derivatization is with radioactive reagent. The characteristic absorp-... 

The intermediate is reactive toward lysine, tyrosine, cysteine, serine, and methionine, to result in amide, ester, and thioester linkages. The selectivity of this reaction is significantly improved by adding an N-h ydroxysuccinimide derivative during the activation step, resulting in the formation of an N-hydroxysuccin i m ide (NHS) ester (Eq. 4.15) ... 

Mathematical Galculate the isoelectric point of each of the following amino acids glutamic acid, serine, histidine, lysine, tyrosine, and arginine. 

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