Histidine lysine and

Write equations for the ionic dissociations of alanine, glutamate, histidine, lysine, and phenylalanine. 

Sowden et al. [4] also did detailed amino acid and amino sugar analyses of the soils from the different dimatic regions. The following amino acids were determined acidic amino acids aspartic and glutamic acids basic amino acids arginine, histidine, lysine and ornithine neutral amino adds, phenylalanine, tyrosine, glycine, alanine, valine, leudne, isoleudne, serine, threonine, proline and hydroxyproline ... 

Rodriquez-Jerez, J., Mora-Ventura, M.T., Lopez-Sabater, E.I. and Hemandez-Herrero, M. (1994). Histidine, lysine, and ornithine decarboxylase bacteria in Spanish salted semipreserved anchovies, J. Food Prot., 57, 784. 

Members of the basic group, histidine, lysine, and arginine, have weak-base side chains. 

Aromatic amines may be converted to their diazonium salts with nitrous acid. The hapten may then be bound via azo linkages to the tyrosine (shown), histidine, lysine, and possibly arginine and tryptophane residues of the carrier protein by mixing the... 

Basic amino acids (histidine, lysine, and arginine) have isoelectric points at pH values of 7.6, 9.7, and 10.8, respectively. These values reflect the weak basicity of the imidazole ring, the intermediate basicity of an amino group, and the strong basicity of the guanidino group. A basic solution is needed in each case to prevent protonation of the basic side chain to keep the amino acid electrically neutral. 

In order to find an explanation for the observed hydrolysis of bonds which are usually difficult to split, it is helpful to examine the nature of the amino acid sequence around the unusual bonds and consider the conditions employed for hydrolysis when these bonds were split. From the data in Table VI it appears that after hydrolysis of bonds formed by the aromatic amino acids and leucine, bonds of methionine, glutamine, asparagine, histidine, lysine, and threonine are most susceptible to chymotrypsin. Certainly, many of these bonds are split slowly, and within the same substrates several bonds formed by the carboxyl groups of the same amino acids were not hydrolyzed to a detectable extent. Thus, in the a-chain of human hemoglobin only one of the four asparaginyl bonds, three of the eight histidyl bonds, and one of the eleven lysyl bonds were hydrolyzed. Similar results are obtained with the other substrates. 

The SCM-cysteine content of the SCMKB proteins ranges between that of wool itself and double this value. Compared with wool these proteins contain high concentrations of proline, serine, and threonine, but low concentrations of aspartic acid, glutamic acid, histidine, lysine, and leucine. In general, reverse trends are shown by the amino acid analyses for SCMKA fractions. SCMKB2 and SCM feather rachis are unique in that they contain virtually no histidine or lysine. In this respect they resemble... 

Applications. A biotinylated GOX-based biosensor was developed based on a new electropolymerized material consisting of a pol3rp3uidyl complex of ruthenium(II) functionalized with a pyrrole group [90]. Because histidine, lysine and arginine functions also coordinate Os /Os , biosensors based on co-electrodeposited GOX, HRP, soybean peroxidase (SBP) and laccase with redox Os /Os polymer have been developed [89]. A metal chelate formed by nickel and nitrilotriacetic acid was used to modify a screen-printed electrode surface. The functionalized support allowed stable attachment of acetylcholinesterase and the resulting biosensor was used for sensitive detection of organophosphorus insecticides [91]. This method is attractive because it ensures a controlled and oriented enzyme immobilization, considerably improving the sensitivity and the detection limit. 

Like laccase and ceruloplasmin, ascorbate oxidase is an acidic protein, with aspartic acid and glutamic acid in excess over histidine, lysine, and arginine. For the amino acid composition see the detailed data in References 3 and 18. Unlike laccase, ascorbate oxidase has a relatively low carbohydrate content, 2.4% vs. approximately 45% (29). 

Three amino acids—histidine, lysine, and arginine—have basic side chains. 

There are no reports to date of enzymes having markedly different pH optima at different temperatures, but given the high d pKa)/dt of the side chains of the ionizable amino acids, especially histidine, lysine, and arginine, it will not be surprising if this is found to be the case. 

Charged group frequency (CHF) is defined as the proportion of amino acid residues that are charged at about pH 6. It is thus equal to the number of aspartic acid, glutamic acid, histidine, lysine, and arginine residues divided by the total number of residues in the molecule (Bigelow 1967). 

The presence of terminal carboxylic and amino groups and other dissociable side chains in aspartic acid, glutamic acid, histidine, lysine, and arginine makes proteins ionizable substances, for which a dissociation equilibrium, pH dependent, is described (Fig. 20). 

Amino acids > as well as ammonia, ) and probably also other primary amines can be determined from the decrease in the wave for phthalaldehyde. In the presence of an excess of phthalalde-hyde a nonreducible compound is formed after the addition of amino compounds. Condensation occurs in most instances in a ratio 1 phthalaldehyde 1 amino acid histidine, lysine and ammonia react in the ratio 3 2. The time necessary for completion of the reaction is between 0 3 hr. (for lysine) and 2-3 hr (for glycine, alanine and ammonia). Because the decrease of the phthalaldehyde wave changes according to the amino acid used, it is necessary in a mixture to separate first the individual amino acids and to use a separate calibration curve for each amino acid. A reaction involving the amino groups of gelatin has also been observed. 

Spectrum of reactivity. All protein nucleophiles can be alkylated by this type of reagent (Table I). Evidence for aflSnity labeling of cysteine, histidine, lysine " and a-amino groups, tyrosine, methionine serine, and glutamic acid has been reported, and it is likely that aspartic acid and threonine can also be labeled. Such a wide spectrum of reactivity is important for successful labeling of residues at the reactive site. 

The haemoglobin of Vertebrates is clearly different from other haemoglobins in containing less arginine and cystine and more histidine, lysine and leucine. 

Amino acids with charged side chains e. g., aspartic acid, glutamic acid, histidine, lysine and arginine. 

Liyasova, M.S., Schopfer, L.M., Lockridge, O., 2012. Cresyl saligenin phosphate, an organophosphorus toxicant, makes covalent adducts with histidine, lysine, and tyrosine residues of human serum albumin. Chem. Res. Toxicol. 25 (8), 1752-1761. 

The isoionic point of the acidic amino acids — aspartic acid and glutamic acid — equals one-half the sum of the pAT values of the a-C02H group and the side chain carboxyl group. Similarly, the isoionic points of the basic amino acids— histidine, lysine, and arginine— equals one-half the sum of the pAf values of the a-NH3 group and the side chain group. Table 27.2 hsts the isoionic points of some amino acids. 

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