A human inborn genetic disease, type I phenylketonuria [13] (PKU) is caused by a mutation in the gene encoding the enzyme phenylalanine dehydrogenase necessary to convert L-phenylalanine (L-Phe) to L-tyrosine, (L-Tyr). The accumulated L-Phe is metabolized by enforced side reaction to phenylpyruvate, phenylacetate, and phenyl-L-lactate excreted with urine, Fig. 1. The excess of phenylalanine hin...

The biosynthetic pathways of arphamenines A and B were studied. Arphamenine A was derived from acetic acid, L-arginine and L-phenylalanine, and arphamenine B from acetic acid, L-arginine and L-tyrosine.

The mechanism of action tyrosinase on monophenols is complex, several processes overlap in time, such as the hydroxylation to o-diphenols, oxidation these o-quinones and evolution latter towards melanin. enzyme's unique but depending chemical nature substrate it may show different exceptions. In this review we want dissect kinetic for enzyme on: a) L-tyrosine, physiological mammalian tyrosinase...

The whole-cell patch-clamp technique was used to monitor the effects of genistein, a tyrosine kinase inhibitor, on membrane currents recorded from isolated guinea pig ventricular myocytes. Under control conditions, genistein (50 micromol/L) did not activate the latent cAMP-regulated Cl- current (ICl). However, in the presence of a subthreshold concentration (1 nmol/L) of the beta-adrenergic ago...

The whole-cell patch-clamp technique was used to monitor the effects of genistein, a tyrosine kinase inhibitor, on membrane currents recorded from isolated guinea pig ventricular myocytes. Under control conditions, genistein (50 mmol/L) did not activate the latent cAMP-regulated Cl current (ICl). However, in the presence of a subthreshold concentration (1 nmol/L) of the b-adrenergic agonist iso...

expression of receptor tyrosine kinase ror1 in a wide variety of cancers has emerged as a new era focusing on targeting this receptor in cancer therapy. our preliminary re-sults indicate the presence of a truncated transcript of ror1 in tumor cells. the trun-cated ror1 encompasses extracellular and transmembrane domains, lacking catalytic kinase domain (ror1-ecd). as enzyme activity is highly d...

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase. Several enantiomorphs of monophenols and o-diphenols were assayed: L-tyrosine, D,L-tyrosine, D-tyrosine; L-alpha-methyltyrosine, D,L-alpha-methyltyrosine; L-dopa, D,L-dopa, D-dopa; L-alpha-methyldopa, D,L-alpha-methyldopa; L-isoprenaline, D,L-isoprenaline and ...