Search results for "Transferases"
showing 10 items of 426 documents
Characterization of thyroid hormone sulfotransferases
1998
Sulfation is an intriguing pathway of thyroid hormone metabolism since it facilitates the degradation of the hormone by the type I deiodinase (D1). This study reports the preliminary characterization of iodothyronine sulfotransferase activities of rat and human liver cytosol and recombinant rSULT1C1 and hSULT1A1 isoenzymes. All these enzyme preparations catalyzed the sulfation of--in decreasing order of efficiency--3,3'-diiodothyronine (3,3'-T2)3,3',5-triiodothyronine (T3) approximately 3,3',5'-triiodothyronine (rT3)thyroxine (T4). 3,3'-T2 sulfotransferase activity was found to be higher in male than in female rat liver, which has also been shown by others for the expression of rSULT1A1 and…
Increased activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, enzymes of collagen biosynthesis, in skeletal muscle of …
1983
The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), and the concentration of 4-hydroxyproline were measured in red and white parts of quadriceps femoris muscle of mice after 3, 10, and 20 sessions of daily endurance training. The activities of PH and GGT increased in the red part of the muscle after training for 3 and 10 times and returned to the control level after 20 training sessions. In the white muscle the increase of PH activity was less than in the red muscle. No alteration in GGT activity was observed in the white muscle. The concentration of hydroxyproline was unchanged in the both types of skeletal muscle. The results suggest that coll…
Aspartate aminotransferase and carbohydrate metabolism of rat brain
1969
E stato determinato il rapporto tra forma «piridossalica» e forma «piridossaminica» dell'aspartato aminotransferasi nell'encefalo totale di ratti albini durante l'ipoglicemia da insulina e l'iperglicemia da allossana. Il rapporto tra le due forme catalitiche dell'enzima e stato considerato un indice dell'efficienza del ciclo degli acidi tricarbossilici, ed e stata prospettata la possibilita che l'aspartato aminotransferasi abbia una funzione regolativa nei riguardi del ciclo.
Lack of Correlation between Liver Tests Abnormalities and Trabectedin Efficacy in the Treatment of Soft Tissue Sarcoma: A Retrospective Study
2015
AbstractElevation in liver transaminases is common in patients treated with the marine antitumor agent trabectedin. However, the impact of trabectedin-related transaminase elevations on treatment outcomes is unclear. This retrospective study investigated the correlation between liver tests abnormalities and treatment outcomes in patients with unresectable advanced or metastatic soft tissue sarcomas (STS) treated with trabectedin 1.5 mg/m2 once every 3 weeks at three reference centers in Italy. The effect of grade 3/4 elevations in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) during the first two cycles and at any time during trabectedin treatment on progression-free su…
Involvement of plasmalogens in post-natal retinal vascular development
2014
Objective: Proper development of retinal blood vessels is essential to ensure sufficient oxygen and nutrient supplies to the retina. It was shown that polyunsaturated fatty acids (PUFAs) could modulate factors involved in tissue vascularization. A congenital deficiency in ether-phospholipids, also termed "plasmalogens'', was shown to lead to abnormal ocular vascularization. Because plasmalogens are considered to be reservoirs of PUFAs, we wished to improve our understanding of the mechanisms by which plasmalogens regulate retinal vascular development and whether the release of PUFAs by calcium-independent phospholipase A2 (iPLA2) could be involved. [br/] Methods and Results: By characterizi…
The G428A Nonsense Mutation in FUT2 Provides Strong but Not Absolute Protection against Symptomatic GII.4 Norovirus Infection
2009
In November 2004, 116 individuals in an elderly nursing home in El Grao de Castellón, Spain were symptomatically infected with genogroup II.4 (GII.4) norovirus. The global attack rate was 54.2%. Genotyping of 34 symptomatic individuals regarding the FUT2 gene revealed that one patient was, surprisingly, a non-secretor, hence indicating secretor-independent infection. Lewis genotyping revealed that Lewis-positive and negative individuals were susceptible to symptomatic norovirus infection indicating that Lewis status did not predict susceptibility. Saliva based ELISA assays were used to determine binding of the outbreak virus to saliva samples. Saliva from a secretor-negative individual boun…
Protective effect of O6-methylguanine-DNA methyltransferase (MGMT) on the cytotoxic and recombinogenic activity of different antineoplastic drugs
1996
The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) removes alkyl groups from the O6 position of guanine in DNA and thus may protect cells against genotoxic effects of agents inducing this lesion. To analyze quantitatively the level of protection mediated by MGMT against antineoplastic drugs, we determined the cytotoxic and recombinogenic (sister-chromatid exchange inducing) effects of various chemotherapeutic agents in a pair of isogenic Chinese hamster cell lines deficient and proficient for MGMT, generated upon transfection with human MGMT cDNA. Furthermore, we compared the responses of the human cell lines HeLa MR (MGMT deficient) and HeLa S3 (MGMT proficient) to the va…
A New Nuclear Function of the Entamoeba histolytica Glycolytic Enzyme Enolase: The Metabolic Regulation of Cytosine-5 Methyltransferase 2 (Dnmt2) Act…
2009
Cytosine-5 methyltransferases of the Dnmt2 family function as DNA and tRNA methyltransferases. Insight into the role and biological significance of Dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. In this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a Dnmt2-binding protein. Enolase, which is known to catalyze the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP), was shown to have both a cytoplasmatic and a nuclear localization in the parasite Entamoeba histolytica. We discovered that enolase acts as a Dnmt2 inhibitor. This unexpected inhibitory activity was antagonized by…
FICC-Seq: a method for enzyme-specified profiling of methyl-5-uridine in cellular RNA.
2019
AbstractMethyl-5-uridine (m5U) is one the most abundant non-canonical bases present in cellular RNA, and in yeast is found at position U54 of tRNAs where modification is catalysed by the methyltransferase Trm2. Although the mammalian enzymes that catalyse m5U formation are yet to be identified via experimental evidence, based on sequence homology to Trm2, two candidates currently exist, TRMT2A and TRMT2B. Here we developed a genome-wide single-nucleotide resolution mapping method, Fluorouracil-Induced-Catalytic-Crosslinking-Sequencing (FICC-Seq), in order to identify the relevant enzymatic targets. We demonstrate that TRMT2A is responsible for the majority of m5U present in human RNA, and t…
Association of Maternal Secretor Status and Human Milk Oligosaccharides With Milk Microbiota: An Observational Pilot Study
2019
Background and Objectives: Breast milk contains several bioactive factors including oligosaccharides (HMO) and microbes that shape the infant gut microbiota. HMO profile is determined by secretor status, however their influence on milk microbiota is still uncovered. This study is aimed to determine the impact of the FUT2 genotype on the milk microbiota during the first month of lactation and the association with HMO. Methods: Milk microbiota from 25 healthy lactating women was determined by quantitative PCR and 16S gene pyrosequencing. Secretor genotype was obtained by PCR-RFLPs and by HMO identification and quantification. Results: The most abundant bacteria were Staphylococcus and Strepto…