Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.2.1.22 (cystathionine beta-synthase)
 965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As a prerequisite for proteome analyses of Corynebacterium glutamicum separation of the cytoplasm and the membrane fraction was optimized and two-dimensional (2-D) gel electrophoresis was established. The resulting 2-D protein maps revealed over 1000 silver-stained protein spots separated by isoelectric point and molecular mass for cytoplasmic proteins and approximately 700 silver-stained spots for proteins of the membrane fraction. Proposing a mean size of 1 kbp per gene the complete C. glutamicum genome of 3 Mbp encodes 3000 different proteins; more than half of these can be located using the maps which are presently available. In this study 10 proteins were identified by N-terminal microsequencing, namely the 35 kDa antigen, antigen 84, ATP synthase subunits alpha, gamma and delta, cysteine synthase, elongation factor G and Ts, enolase, and rotamase. For seven sequences, corresponding proteins could not be identified. Additionally, two proteins were specifically detected by immunoblotting, a corynebacterial porin and the cytoplasmic protein threonine dehydratase. The methods and 2-D maps established in this study will be the basis for comparative studies of protein expression and a detailed proteome analysis of C. glutamicum.
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PMID:Mapping and identification of Corynebacterium glutamicum proteins by two-dimensional gel electrophoresis and microsequencing. 993 18

We have employed proteomics to identify proteins upregulated in the amastigote life-stage of Leishmaniapanamensis, using axenically-differentiated forms as models of authentic intracellular parasites. Resolution of the soluble proteomes of axenic amastigotes and promastigotes by two-dimensional electrophoresis (2DE) in the neutral pI range (5-7) revealed equivalent numbers of protein spots in both life-stages (644-682 using Coomassie Blue and 851-863 by silver staining). Although representing a relatively low proportion (8.1-10.8%) of the predicted 8000 gene products of Leishmania, these proteome maps enabled the reproducible detection of 75 differentially-regulated protein spots in amastigotes, comprising 24 spots "uniquely" expressed in this life-stage and 51 over-expressed by 1.2-5.7-fold compared to promastigotes. Of the 11 amastigote-specific spots analysed by mass spectrometry (MS), 5 yielded peptide sequences with no orthologues in Leishmania major, and the remaining 6 were identified as 7 distinct proteins (some of which were truncated isoforms) representing several functional classes: carbohydrate/energy metabolism (fructose 1,6-bisphosphate aldolase, glucose 6-phosphate dehydrogenase, pyruvate dehydrogenase), stress response (heat shock protein [HSP] 83), cell membrane/cytoskeleton (beta-tubulin), amino acid metabolism (cysteine synthase) and cell-cycle (ran-binding protein). Four additional over-expressed spots were tentatively identified as HSPs 60 and 70 and HSP 70-related proteins -1 and -4 by positional analogy with these landmark proteins in the Leishmania guyanensis proteome. Our data demonstrate the feasibility of proteomics as an approach to identify novel developmentally-regulated proteins linked to Leishmania differentiation and intracellular survival, while simultaneously pinpointing therapeutic targets. In particular, the amastigote-specific expression of cysteine synthase underlines the importance of de novo cysteine synthesis both as a potential parasite virulence factor and as a major metabolic difference from mammalian host cells.
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PMID:Identification of developmentally-regulated proteins in Leishmania panamensis by proteome profiling of promastigotes and axenic amastigotes. 1653 Feb 78

Hydrogen sulfide (H2S) is recognized as a neuromodulator as well as neuroprotectant in the brain. H2S can be produced from cysteine by enzymes such as cystathionine beta-synthase. However, a mechanism for releasing H2S under physiologic conditions has not been identified. Here we show that H2S is released from bound sulfur, an intracellular store of sulfur, in neurons and astrocytes of mice and rats in the presence of physiologic concentrations of endogenous reducing substances glutathione and cysteine. The highest pH to release H2S from another sulfur store, acid-labile sulfur, which is localized mainly in mitochondria, is 5.4. Because mitochondria are not in the acidic condition, acid-labile sulfur may not be a physiologic source of H2S. Free H2S is immediately absorbed and stored as bound sulfur. Our novel method, using silver particles to measure free H2S, shows that free H2S is maintained at a low level in basal conditions. Alkalinization of the cytoplasm is required for effective release of H2S from bound sulfur, and this condition is achieved in astrocytes by the high concentrations of extracellular K+ that are normally present when nearby neurons are excited. These data present a new perspective on the regulation of H2S in the brain.
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PMID:A source of hydrogen sulfide and a mechanism of its release in the brain. 1875 2

A two year-old male child presented with cutis marmorata congenita universalis, brittle hair, mild mental retardation, and finger spasms. Biochemical findings include increased levels of homocysteine in the blood-106.62 micromol/L (normal levels: 5.90-16 micromol/L). Biochemical tests such as the silver nitroprusside and nitroprusside tests were positive suggesting homocystinuria. The patient was treated with oral pyridoxine therapy for three months. The child responded well to this therapy and the muscle spasms as well as skin manifestations such as cutis marmorata subsided. The treatment is being continued; the case is reported here because of its rarity. Homocysteinuria arising due to cystathionine beta-synthase (CBS) deficiency is an autosomal recessive disorder of methionine metabolism that produces increased levels of urinary homocysteine and methionine It manifests itself in vascular, central nervous system, cutaneous, and connective tissue disturbances and phenotypically resembles Marfan's syndrome. Skin manifestations include malar flush, thin hair, and cutis reticulata / marmorata.
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PMID:Homocystinuria due to cystathionine beta synthase deficiency. 1879 62