N-benzoyl-L-tyrosine

FIG. 7 Dependence on the water/surfactant molar ratio of (a) the maximal reaction rate normalized to the enzyme concentration, V/E, of a-chymotrypsin-catalyzed hydrolysis of N-benzoyl-L-tyrosine p-nitroanilide, and (b) the rotational frequency, v, of the spin label in the active site of the enzyme in the system AOT-water/glycerol-octane. Water/glycerol volume ratios 1—100 0 2—80 20, 3—50 50, 4—20 80, 5—6 94. Dashed lines show V/Eq and v values in aqueous solution. (From Ref. 42.)... 

Many proteinases cleave not only peptide bonds but also ester bonds. Determinations of trypsin, chymo-trypsin, papain, and some other enzymes are based on this property. The standard substrate for activity determination of trypsin and papain is N-benzoyl-L-arginine ethyl ester (BARE), and for chymotrypsin, N-benzoyl-L-tyrosine ethyl ester. For example ... 

Trypsin, chymotrypsin, and cathepsin C (all from bovine), and the synthetic substrates glycyl-L-phenylalanine p-naphtylamide (GPNA), 4-phenylazo benzyloxy-car-bonyl-pro-leu-gly-pro-D-arg (PZ-peptide), N-benzoyl-L-tyrosine ethyl ester (BTEE), and Na-benzoyl-DL-arginine p-nitroanilide (BAPNA), were purchased from Sigma Chemical Co (St. Louis, MO). Fresh bluefish (Pomatomus saltatrix) and sheephead samples were purchased from a local fish market (Waldman Plus, Montreal, PQ) and kept in iCe until ready for use. 

Ci8Hi9NOi, N-Benzoyl-L-tyrosine ethyl ester, 38B, 500 Cl 8 2il2N2O5, 3,5-Iodo-L-thyronine N-methylacetamide, 38B, 500 C18H22N2OSS, Glycyl-L-phenylalanine p-toluenesulphonate, 38B, 499 Cl8H2 5N3O4, N-Benzyloxycarbonyl-a-aminoisobutyryl-L-prolyl methyl-amide, 45B, 525... 

A solution was made of N-benzyl-L-tyrosine (5.7 g, 20 mmols) and N-methylmorphollne (2,04 g, 20 mmols) In 60 ml of THF, at -15°C, and to it was added ethyl chloroformate (2,08 g, 20 mmols), After 12 minutes, p-aminobenzoic acid (2.74 g, 20 mmols) dissolved in 25 ml of THF and 0.38 g of p-toluenesulfonic acid (2 mmols) were added, and the temperature allowed to rise to 5°C. After 2 hours and forty minutes, the mixture was poured into 1 liter of 0,1 N cold HCI, stirred one-half hour, filtered and dried, to give 8,7 g, MP 192°-223°C. The product was recrystallized from 90 ml methanol and 40 ml water, to give 6 g (74%) of product, N-benzoyl-L-tyrosyl-p-amlnobenzoic acid, MP 240°-242°C. 

Abbreviations ADA, adenosine deaminse BAEE, N,a-benzoyl-L-arginine ethyl ester, BTEE, N,oc-benzoyl-L-tyrosine ethyl ester BTNA, N,a-benzoyl-L-tyrosine-p-nitroanilide ZAPA, N,a-benzoylcarbonyl-L-arginine-p-nitroanilide. 

C11H12CIN04 N-(2-chloroacetyl)-L-tyrosine 1145-56-8 25.00 1.3161 2 21990 C11H13N03 N-benzoyl-L-alanine methyl ester 7244-67-9 25.00 1.1676 2... 

The following abbreviations are used in the text DEAE-cellulose, diethylamino-ethyl-cellulose CM-cellulose, carboxymethyl-cellulose DFP, diisopropylphospho-fluoridate ATEE, acetyl-n-tyrosine ethyl ester BAEE, benzoyl-L-arginine ethyl ester Tris, tris(hydroxymethyl)aminomethane. 

O-Acyltyrosine derivatives bear the disadvantage of being active esters capable of acylating amino groups or other nucleophiles in a particularly efficient manner by intermolecular O—> N transfer (Scheme 9). Due to the reactivity of these phenyl esters, acyl groups such as acetyl or benzoyl, which are commonly used in carbohydrate chemistry, cannot be recommended for the protection of the tyrosine hydroxy group.f l... 

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