Cysteinic acid

Sulfonic acids represented by the general formula RS03H are found in nature. Examples are the amino acids taurine (1) and cysteinic acid (2)1. 

You fear that the cysteine and methionine residues of your proteins oxidize to cysteine acid and methionine sulfoxide Then gas the lEF solutions beforehand with nitrogen. 

N, N, N -tetramethyl-p-phenylenediamine) difference spectrum using an extinction coefficient, 72,000 M cm according to (12). For amino acid analysis, a complex preparation was hydrolyzed either by using 6N HCl or 4N methane sulfonic acid. The hydrolyzate was analyzed on a Hitachi amino acid analysis system equipped with a post-column o-phthalaldehyde labeling system. Iron was determined colorimetrically according to (13). Cysteine residues were determined after converted into cysteinic acid. 

Food DM (g/kg) NE growing pigs and lactating sows (MJ/kg) NE pregnant sows (MJ/kg) Digestible phosphorus (g/kg) Standardised ileal digestible amino Lysine Methionine + Threonine cysteine acid (g/kg) Tryptophan... 

CJH4O5, H02CCH(0H)C02H. Colourless crystals with IH O lost at 60 C. M.p. IhO C (decomp.). Prepared by heating dinitrotartaric acid in aqueous alcohol, taurine, aminoethylsulpbonic acid, C2H7NO3S, NHj CHj CH SOjH. Crystallizes in columns, decomposing at 317 C. In combination with cholic acid it forms one of the bile acids. It is formed in the liver from cysteine. 

In his cephalosporin synthesis methyl levulinate was condensed with cysteine in acidic medium to give a bicyclic thiazolidine. One may rationalize the regioselective formation of this bicycle with the assumption that in the acidic reaction mixture the tMoI group is the only nucleophile present, which can add to the ketone. Intramolecular amide formation from the methyl ester and acid-catalyzed dehydration would then lead to the thiazolidine and y-lactam rings. The stereochemistry at the carboxylic acid a-... 

Insulin has 51 ammo acids divided between two chains One of these the A chain has 21 ammo acids the other the B chain has 30 The A and B chains are joined by disul fide bonds between cysteine residues (Cys Cys) Figure 27 10 shows some of the infor matron that defines the ammo acid sequence of the B chain... 

Sanger also determined the sequence of the A chain and identified the cysteine residues involved m disulfide bonds befween fhe A and B chains as well as m fhe disulfide linkage wifhin fhe A chain The complefe insulin sfruefure is shown m Figure 27 11 The sfruefure shown is fhaf of bovine insulin (from cattle) The A chains of human insulin and bovine insulin differ m only fwo ammo acid residues fheir B chains are identical except for the ammo acid at the C terminus... 

The primary structure of a peptide is given by its ammo acid sequence plus any disulfide bonds between two cysteine residues The primary structure is determined by a systematic approach m which the protein is cleaved to smaller fragments even individual ammo acids The smaller fragments are sequenced and the mam sequence deduced by finding regions of overlap among the smaller peptides... 

Chlorine Benzoyl peroxide L-Ascorbic acid L-Cysteine... 

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