Tryptophan analogs

For calmodulin and other tyrosine-only protons, a genetically inserted tryptophan residue can serve as a useful probe. However, most proteins contain tryptophan, and in 

SHW and TAW difi from each other and frcrni tiypto-phan in their spectral properties. In water, SHW displays a higher quantum yield than tiyptopban (0.275 versus 0.14). It is 1 s itive to solvent polari than tiyptophan and displ s an emission ntaximiim near 339 nm (Hgure 16.60). TAW is highly sensitive to solvit pdarity. In wat, its quantum yidd is low, near 0.017, with an emission maximum near 403 nm. 

The advantages of SHW and TAW can be seen thdr use in studies of more complex biodiCTUcal mixtures. SHW was used to rq lace the tyrosine residue in insiiKa. This allowed the flutnescence of SHW-insiilin to be used to study its binding to the insulin receptor. Such studies would not be possible using the tyrosine fiutvescenoe oi 

2O C citali ial293BiB.)Rew dandiepiiiiled,wMipeneiBio0, from Ref. I 2, Copyright 019. Cie ndeeUolvemQr Press. 

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To make tryptophan analogs, Gronowitz and coworkers conducted a pyrrole annulation from an aminoiodopyrimidine utilizing the Larock indole synthesis conditions (see Section 1.10.) [80]. They prepared heterocondensed pyrrole 115 by treating 4-amino-5-iodopyrimidine 114 with trimethylsilyl propargyl alcohol under the influence of a palladium catalyst The regiochemical outcome was governed by steric effects. 

Synthesized tyrosine-, phenylalanine-, tetrahydroisoquinoline-, tetralin- and tryptophan analogs Chirobiotic R Reversed-phase mode H20/Me0H Polar organic mode MeOH/HOAc/TEA 269... 

This enzyme [EC 4.1.99.1], also known as L-tryptophan indole-lyase, catalyzes the hydrolysis of L-tryptophan to generate indole, pyruvate, and ammonia. The reaction requires pyridoxal phosphate and potassium ions. The enzyme can also catalyze the synthesis of tryptophan from indole and serine as well as catalyze 2,3-elimination and j8-replacement reactions of some indole-substituted tryptophan analogs of L-cysteine, L-serine, and other 3-substituted amino acids. 

Starting from resin-bound N-acylated dipeptides 11 having tryptophan or a tryptophan analog as the C-terminal amino acid, a mixture-based combinatorial library of 46,750 indolepyridoimidazoles 12 was synthesized by double cyclodehydration under Bischler-Napieralski conditions (POCl3, dioxane, 100°) (Fig. 4).23 Twenty-two tryptophan analogs, 25 amino acids, and 85 carboxylic acids were used for the library synthesis. 

SPECTRAL ENHANCEMENT OF RECOMBINANT PROTEINS WITH TRYPTOPHAN ANALOGS ... 

Spectral Enhancement of Proteins with Tryptophan Analogs... 

L-Tryptophan Analog resistant mutant of P. hydrogenothermophila First example for the production from CO,... 

Sidransky, H., Verney, E., and Kurl, R., Comparison of effects of L-tryptophan and a tryptophan analog, D, L-beta-(l-naphthyl)alanine, on processes relating to hepatic protein synthesis in rats, ]. Nutr., 120[10], 1157, 1990. 

Addition of tryptophan analogs also led to the corresponding analogs of pyrrolnitrin (25). 

Ross A, Szabo A G, Hogne C W V (1997). Enhancement of protein spectra with tryptophan analogs Flnorescence spectroscopy of protein-protein and protein-nncleic acid interactions. Methods Enzymol. 278 151-190. 

Fig. 2. Induction of alkaloid synthesis by tryptophan and tryptophan analogs.

Fig. 3. Induction of Dimethylallyltryptophan Synthetase by Tryptopahn and Tryptophan Analogs.

Figure 3 9 Biosynthesis of natural and unnatural cyclomarin and cyclomarazine analogs. Supplementing cultures of the S. arenicola cymD mutant with tryptophan analogs yields known and novel cyclomarins and cyclomarazines. Abbreviations A, adenylation domain C, condensation domain M1-M7, modules 1-7 MT, methyltransferase T, thiolation domain and TE, thioesterase.

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