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Chang Seon Ryu et al.
Biochemical pharmacology, 85(2), 197-206 (2012-11-06)
Tamoxifen (TAM) resistance is a main cause of therapeutic failure in breast cancers. Although methionine dependency is a phenotypic characteristic of tumor cells, the role of sulfur amino acid metabolism in chemotherapy resistance remains to be elucidated. This study compared
Michael Linnebank et al.
Neuro-degenerative diseases, 7(6), 373-378 (2010-06-05)
Increased plasma homocysteine levels have been described as an independent risk factor for Alzheimer's disease (AD), but the underlying pathophysiology is unclear. This single-center, cross-sectional, correlational study analyzed homocysteine metabolism in 60 AD patients and 60 control subjects. Fasting plasma
Vidhi Mishra et al.
Biochemistry, 51(48), 9763-9772 (2012-11-15)
The bacterial 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) enzyme is a multifunctional enzyme that catalyzes the hydrolysis of the N-ribosidic bond of at least four different adenosine-based metabolites: S-adenosylhomocysteine (SAH), 5'-methylthioadenosine (MTA), 5'-deoxyadenosine (5'-DOA), and 6-amino-6-deoxyfutalosine. These activities place the enzyme at the
E A Struys et al.
Clinical chemistry, 46(10), 1650-1656 (2000-10-06)
Available methods for the determination of nanomolar concentrations of S:-adenosylmethionine (SAM) and S:-adenosylhomocysteine (SAH) in plasma and cerebrospinal fluid (CSF) are time-consuming. We wished to develop a method for their rapid and simultaneous measurement. We used tandem mass spectrometry (MS/MS)
P A LeWitt et al.
Neurology, 42(11), 2111-2117 (1992-11-01)
We used two analytic methods (a multichannel coulometric electrode array with high-performance liquid chromatography, and gas chromatography-mass spectrophotometry) to measure CSF dopamine (DA) and its metabolites in mildly affected, unmedicated subjects with Parkinson's disease (PD). The mean (+/- SD) concentration
Siew Pheng Lim et al.
Methods in molecular biology (Clifton, N.J.), 1030, 249-268 (2013-07-04)
Flavivirus NS5 is the most conserved protein amongst the flavivirus proteins and is an essential enzyme for viral mRNA capping and replication. It encodes a methyl-transferase (MTase) domain at its N-terminal region which carries out sequential N7 and 2'-O methylation
Maryam Goudarzi et al.
Journal of proteome research, 14(9), 4039-4049 (2015-08-12)
Despite considerable research into the environmental risks and biological effects of exposure to external beam γ rays, incorporation of radionuclides has largely been understudied. This dosimetry and exposure risk assessment is challenging for first responders in the field during a
Lin Huang et al.
Nucleic acids research, 48(13), 7545-7556 (2020-06-11)
While most SAM riboswitches strongly discriminate between SAM and SAH, the SAM/SAH riboswitch responds to both ligands with similar apparent affinities. We have determined crystal structures of the SAM/SAH riboswitch bound to SAH, SAM and other variant ligands at high
Rima Obeid et al.
Clinical chemistry, 53(2), 326-333 (2007-01-04)
B-vitamins (folate, B(12)) are important micronutrients for brain function and essential cofactors for homocysteine (HCY) metabolism. Increased HCY has been related to neurological and psychiatric disorders. We studied the role of the B-vitamins in HCY metabolism in the brain. We
Wolfgang Herrmann et al.
Clinical chemistry and laboratory medicine, 51(3), 639-647 (2012-11-28)
Vitamin D and vitamin B deficiency are common in elderly subjects and are important risk factors for osteoporosis and age-related diseases. Supplementation with these vitamins is a promising preventative strategy. The objective of this study was to evaluate the effects
Paula Dominguez-Salas et al.
The American journal of clinical nutrition, 97(6), 1217-1227 (2013-04-12)
Animal models show that periconceptional supplementation with folic acid, vitamin B-12, choline, and betaine can induce differences in offspring phenotype mediated by epigenetic changes in DNA. In humans, altered DNA methylation patterns have been observed in offspring whose mothers were
M Naoi et al.
Mechanisms of ageing and development, 111(2-3), 175-188 (2000-02-03)
Dopamine neurons in the substantia nigra of human brain are selectively vulnerable and the number decline by aging at 5-10% per decade. Enzymatic and non-enzymatic oxidation of dopamine generates reactive oxygen species, which induces apoptotic cell death in dopamine neurons.
Nithya Narayanan et al.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 28(8), 3411-3422 (2014-04-18)
Hyperhomocysteinemia (HHcy) is prevalent in patients with hypertension and is an independent risk factor for aortic pathologies. HHcy is known to cause an imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), leading to the accumulation of collagen
Conrad Wagner et al.
The American journal of clinical nutrition, 86(6), 1581-1585 (2007-12-11)
It is widely accepted that elevated plasma total homocysteine is an independent risk factor for vascular disease. The relation is believed to be causal, but there is no generally accepted mechanism for the pathophysiology involved. The metabolic precursor of homocysteine
S Melnyk et al.
Clinical chemistry, 46(2), 265-272 (2000-02-05)
The relative changes in plasma and intracellular concentrations of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) may be important predictors of cellular methylation potential and metabolic alterations associated with specific genetic polymorphisms and/or nutritional deficiencies. Because these metabolites are present in nanomolar
Brian Fowler
Seminars in vascular medicine, 5(2), 77-86 (2005-07-28)
Homocysteine is derived from the essential amino acid methionine and plays a vital role in cellular homeostasis in man. Homocysteine levels depend on its synthesis, involving methionine adenosyltransferase, S-adenosylmethionine-dependent methyltransferases such as glycine N-methyltransferase, and S-adenosylhomocysteine hydrolase; its remethylation to
Y Miura
The Kurume medical journal, 47(4), 267-272 (2001-02-24)
Plasma beta-phenylethylamine (PEA) levels were determined in 27 patients with Parkinson's disease (PD) in order to evaluate its relation with the severity or clinical course of PD. The plasma PEA concentrations in PD patients were significantly lower (mean +/- SD
Jae-Eun Kim et al.
American journal of physiology. Renal physiology, 308(7), F749-F764 (2015-02-05)
Mature microRNA (miRNA) acts as an important posttranscriptional regulator. We aimed to profile vasopressin-responsive miRNAs in kidney inner medullary collecting duct cells and to identify aquaporin-2 (AQP2)-targeting miRNAs. Microarray chip assay was carried out in inner medullary collecting duct tubule
Desirée E C Smith et al.
Clinical chemistry and laboratory medicine, 50(9), 1641-1647 (2012-09-11)
Disturbances in the levels of one-carbon (1C) metabolism metabolites have been associated with a wide variety of neuropsychiatric diseases. Cerebrospinal fluid (CSF) levels of homocysteine (Hcy) and the other 1C metabolites, nor their interrelatedness and putative determinants, have been studied
Xiaohu Guo et al.
eLife, 10 (2021-02-11)
The first S-adenosyl methionine (SAM) degrading enzyme (SAMase) was discovered in bacteriophage T3, as a counter-defense against the bacterial restriction-modification system, and annotated as a SAM hydrolase forming 5'-methyl-thioadenosine (MTA) and L-homoserine. From environmental phages, we recently discovered three SAMases
S Engelborghs et al.
Neurochemical research, 28(8), 1145-1150 (2003-07-02)
To study changes in amino acid metabolism and biogenic amines in Parkinson's disease, we set up a prospective study and measured biogenic amines, their main metabolites, and 22 different amino acids, in cerebrospinal fluid of Parkinson's disease patients (n =
Coen van Guldener et al.
Seminars in vascular medicine, 5(2), 201-208 (2005-07-28)
Renal insufficiency is invariably accompanied by elevated plasma concentrations of the sulfur-containing and potentially vasculotoxic amino acid homocysteine. There is a strong relationship between glomerular filtration rate and plasma homocysteine concentration. Unlike creatinine, however, homocysteine is avidly reabsorbed in the
Kyung-Hoon Lee et al.
Biochemistry, 48(42), 10162-10174 (2009-09-10)
RimO, encoded by the yliG gene in Escherichia coli, has been recently identified in vivo as the enzyme responsible for the attachment of a methylthio group on the beta-carbon of Asp88 of the small ribosomal protein S12 [Anton, B. P.
M S Hershfield et al.
Cancer research, 43(7), 3451-3458 (1983-07-01)
A patient with refractory T-cell acute lymphoblastic leukemia was treated with eight courses of the adenosine deaminase inhibitor, 2'-deoxycoformycin (dCF), over a 5-month period. After developing resistance to dCF, he responded to treatment with the combination of dCF and 9-beta-D-arabinofuranosyladenine
Apolline Imbard et al.
Clinical chemistry and laboratory medicine, 51(3), 683-692 (2012-10-26)
Choline is essential for mammalian cell function. It plays a critical role in cell membrane integrity, neurotransmission, cell signaling and lipid metabolism. Moreover, choline is involved in methylation in two ways: a) its synthesis requires methyl groups donated by S-adenosyl-methionine
U Delabar et al.
Journal of chromatography. B, Biomedical sciences and applications, 724(2), 231-238 (1999-04-29)
A sensitive and rapid method for measuring simultaneously adenosine, S-adenosylhomocysteine and S-adenosylmethionine in renal tissue, and for the analysis of adenosine and S-adenosylhomocysteine concentrations in the urine is presented. Separation and quantification of the nucleosides are performed following solid-phase extraction
Valentina Medici et al.
Hepatology (Baltimore, Md.), 57(2), 555-565 (2012-09-05)
Hepatic methionine metabolism may play an essential role in regulating methylation status and liver injury in Wilson's disease (WD) through the inhibition of S-adenosylhomocysteine hydrolase (SAHH) by copper (Cu) and the consequent accumulation of S-adenosylhomocysteine (SAH). We studied the transcript
George I Papakostas et al.
The Journal of clinical psychiatry, 75(8), 855-863 (2014-05-13)
Specific genetic or biological markers may predict inadequate response to therapy for major depressive disorder (MDD). The objective of the current post hoc analysis was to evaluate the effect of specific biological and genetic markers on the antidepressant efficacy of
Mingxu You et al.
Proceedings of the National Academy of Sciences of the United States of America, 112(21), E2756-E2765 (2015-05-13)
Riboswitches are natural ligand-sensing RNAs typically that are found in the 5' UTRs of mRNA. Numerous classes of riboswitches have been discovered, enabling mRNA to be regulated by diverse and physiologically important cellular metabolites and small molecules. Here we describe
Ji Hye Kim et al.
Biochemical pharmacology, 85(8), 1042-1056 (2013-01-29)
Transmethylation is an important reaction that transfers a methyl group in S-adenosylmethionine (SAM) to substrates such as DNA, RNA, and proteins. It is known that transmethylation plays critical roles in various cellular responses. In this study, we examined the effects
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