Tyrosyl

Figure 4.15 Schematic diagram of the enzyme tyrosyl-tRNA synthetase, which couples tyrosine to its cognate transfer RNA. The central region of the catalytic domain (red and green) is an open twisted a/p stmcture with five parallel p strands. The active site is formed by the loops from the carboxy ends of P strands 2 and S. These two adjacent strands are connected to a helices on opposite sides of the P sheet.

Figure 4.16 A schematic view of the active site of tyrosyl-tRNA synthetase. Tyrosyl adenylate, the product of the first reaction catalyzed by the enzyme, is bound to two loop regions residues 38-47, which form the loop after p strand 2, and residues 190-193, which form the loop after P strand 5. The tyrosine and adenylate moieties are bound on opposite sides of the P sheet outside the catboxy ends of P strands 2 and 5.

Figure 4.17 Schematic diagram of bound tyrosine to tyrosyl-tRNA synthetase. Colored regions correspond to van der Waals radii of atoms within a layer of the structure through the tyrosine ring. Red is bound tyrosine green is the end of P strand 2 and the beginning of the following loop region yellow is the loop region 189-192 and brown is part of the a helix in loop region 173-177.

Figure 4.18 Side chains of the tyrosyl-tRNA synthetase that form hydrogen bonds to tyrosyl adenylate. Green residues are from p strand 2 and the following loop regions, yellow residues are from the loop after P strand S, and brown residues are from the a helix before P strand S. (Adapted from T. Wells and A. Fersht, Nature 316 656-657, 1985.)...

Brick, R, Bhat, T.N., Blow, D.M. Structure of tyrosyl-tRNA synthetase refined at 2.3 A resolution. Interaction of the enzyme with the tyrosyl adenylate intermediate. /. Mol. Biol. 208 83-98, 1988. 

This inhibitor does not form a covalent bond to Ser 195 but one of its carboxy oxygen atoms is in the oxyanion hole forming hydrogen bonds to the main-chain NH groups of residues 193 and 195. The tyrosyl side chain is positioned in the specificity pocket, which derives its specificity mainly from three residues, 216, 226, and 189, as we shall see later. The main chain of... 

Chemical Name L-asperaginyl-L-erginyl-L-velyl-L-tyrosyl-L-valyl-L-histidyl-L-protyl-L-phenylalanine... 

L-Asperaginyl-L-arginyl-L-velyl-L-tyrosyl-L-velyl-L-hlstIdyl-L-prolyl-L-phenylelenine methyl ester trihydrochloride Sodium hydroxide... 

Common Name N-Benzoyl-L-tyrosyl-p-aminobenzoic acid Structural Formula ... 

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. 

L-pyroglutamyl-L-glutaminyl-L-aspartyl-L-tyrosyl-L-threonyl-glycyl-L-tryptophanyl-... 

Benzylmercaptopropionyl-L-tyrosyl-L-phenyalanyl-L-glutaminyl-L-asparaginyl-S-benzyl-L-cysteinyl-L-prolyl-N-tosyl-D-arginyl glycinamide Sodium Ammonia Acetic acid... 

N-Carbobenzoxy-L-glutaminyl-L-asperaginyl-S-benzyl-L-cystainyl azide N-Carbobenzoxy-S-benzyl-L-cysteinyl-L-tyrosyl-L-phanylalanine azide Sodium Ammonia... 

The starting material in the following synthesis is t-butvloxycarbonyl-L-aspartyl-L-tyrosyl-L-methionylglvcyl-L-tryptophyl-L-methionvl-L-aspartvl-L-phenylalanine amide designated (SMI. 

N-Carbobenzoxy-S-benzyl-L-cysteinyl-L-tyrosyl-L-phenylalanine azide Ornipressin... 

Chymotrypsin-like proteinases are serine proteinases that recognize pqDtide residues with aromatic side chains (phyenylalanyl or tyrosyl residues) and that effect hydrolysis of the polypeptide chain on the carboxy-terminal side of these residues. Examples of chymotrypsin-like proteinases are chymotrypsin and cathepsin-G. 

CN 5-oxo-L-prolyl-L-glutaminyl-L-a-aspartyl-O-sulfo-L-tyrosyl-L-threonylglycyl-L-tryptophyl-L-methionyl-L-a-aspartyl-L-phenylalanin amide... 

CN L-cysteinyl-L-tyrosyl-L-isoleucyl-L-glutaminyl-L-asparaginyl-L-cysteinyl-L-prolyl-L-leucylglycinamide cyclic (1—>6)-disulfide... 

FLPEP—Fluoresceinated ff-formyl-norleucyl-leucyl-phenyl-alanyl-norleucyl-tyrosyl-lysine. 

PEP— -Formylhexapeptide or N-formyl-norleucyl-leucyl-phenylalanyl-norleucyl-tyrosyl-lysine. 

---