Tyrosine aminotransferase purified from epimastigotes of Trypanosoma cruzi displays an additional activity of alanine aminotransferase, absent in all other tyrosine aminotransferases characterized so far. Since the parasite's genome contains a high number of copies of the tyrosine aminotransferase gene, we could not rule out the possibility that two very similar proteins, with changed specifici...

The synthesis of the enzyme tyrosine aminotransferase in HTC cells (an established line of rat hepatoma cells) is inducible by glucocorticoid hormones only during the latter part of G1 phase and throughout S phase in the cell generation cycle. We have earlier shown that during the first few hours of G1 phase when the enzyme cannot be induced, its synthesis is constitutive, presumably using as t...

Coupling mitosis to the completion of DNA replication in cycling embryonic extracts from Xenopus eggs appears to rely on blocking the activation of the tyrosine-phosphorylated p34cdc2/cyclin B, which continues to build up when S phase is inhibited by adding unreplicated DNA (Smythe, C., and Newport, J. W., Cell, 68: 787-797, 1992). We show here that a similar mechanism might be operative in hum...

The SgcC5 condensation enzyme catalyzes the attachment of SgcC2-tethered (S)-3-chloro-5-hydroxy-β-tyrosine (2) to the enediyne core in C-1027 (1) biosynthesis. It is reported that SgcC5 (i) exhibits high stereospecificity toward the (S)-enantiomers of SgcC2-tethered β-tyrosine and analogues as donors, (ii) prefers the (R)-enantiomers of 1-phenyl-1,2-ethanediol (3) and analogues, mimicking the e...

after alzheimer's disease, parkinson's disease is the most common nerve-damaging disease. parkinson's is a progressive and chronic disease where cells secrete dopamine-cut black flesh and in the absence of dopamine in the brain destroyed the irregular body movements. man eats the food that causes the formation of the neurotransmitters. tthree neurotransmitters: dopamine, serotoni...

Mammalian sperm are not able to fertilize immediately upon ejaculation; they become fertilization-competent after undergoing changes in the female reproductive tract collectively termed capacitation. Although it has been established that capacitation is associated with an increase in tyrosine phosphorylation, little is known about the role of this event in sperm function. In this work we used a...

In this paper we report the effect of cetyltrimethylammonium bromide, CTAB on the oxidative degradation of tyrosine by permanganate. The reaction rate bears a first-order dependence on the [MnO(4)(-)] under pseudo-first-order conditions (large excess of [tyrosine] for at least 10 times over [MnO(4)(-)]) in presence of 10.0x10(-4)moldm(-3) CTAB. The effect of total [CTAB] on the reaction rate wa...

Using the Computational methods, the interaction effect of Tyrosine Amino acid on Graphene wasinvestigated. For this purpose, the Density Functional Theory (DFT) in the ground state of 6-31Gwas used, and the interaction effects of Tyrosine on Graphene was investigated through attachmentto three different base positions. Different parameters such as energy levels, the amount ofChemical Shift in ...

Background and Aims: Hypertyrosinemia type 3 (HT3) is an inherited error in tyrosine metabolism caused by a mutation in the 4-hydroxyphenylpyruvate dioxygenase (HPD) gene. Here we report a one and half-year-old girl infant who was diagnosed based on increased serum tyrosine levels and increased urinary excretion of p-hydroxyphenyl derivatives. Materials and Methods: The proband was one and ha...

The 145-kDa phospholipase C isozyme, PLC-gamma, is an excellent substrate for the epidermal growth factor (EGF) receptor both in vivo and in vitro. We now demonstrate that EGF treatment of HSC-1 cells, a human squamous cell carcinoma-derived cell line that expresses high levels of the EGF receptor, rapidly induces tyrosine phosphorylation of two-thirds of the total cellular PLC-gamma pool. A tw...