L-Phenylalanine and L-tyrosine were completely catabolized through homogentisate by Streptomyces setonii 75Vi2 but only partially degraded by Streptomyces badius 252, Streptomyces sioyaensis P5, Streptomyces viridosporus T7A, and Streptomyces sp. strain V7. Intermediates of catabolism were confirmed by thin-layer, gas, and high-pressure liquid chromatography. Homogentisate 1,2-dioxygenase was p...

L-tyrosine, a precurosr to melanin, has recently been shown to be a regulator of the melanogenic pathway in some cultured melanoma cell lines. In this paper we demonstrated that L-tyrosine, besides increasing binding capacity for MSH, decreased cooperativity between MSH receptors and increased the level of tyrosinase induction by MSH. Apparently, regulation of MSH receptor activity by L-tyrosin...

background & objectives: anaplastic lymphoma kinase (alk) is a receptor tyrosine kinase involved in the genesis of several human cancers. alk was initially identified because of its involvement in anaplastic large cell lymphoma (alcl). alk is believed to foster tumorigenesis following activation by autocrine and/or paracrine growth loops. studies reveal that the presence of anti-alk antibod...

In the last few decades, enzymatic production of 3,4-dihydroxyphenyl-L-alanine (L-dopa) using tyrosine phenol-lyase (Tpl) has been industrialized. This method has an intrinsic problem of tyrosine contamination because Tpl is synthesized under tyrosine-induced conditions. Herein, we constructed a hyper-L-dopa-producing strain by exploiting a mutant TyrR, an activator of tpl. The highest producti...

In this study, the antibacterial and cytotoxic activities of some amino acid methyl esters (L-methionine, L-phenylalanine, L-histidine, L-lysine, L-tryptophan, L-tyrosine) were investigated. The effect ester compounds on performance was determinated against Gram-negative Gram-positive bacteria. cell viability investigated cancerous non-cancerous lines using MTS assay. results showed substances ...