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61.
Purification and characterization of 2-enoyl-CoA reductase from bovine liver. 总被引:1,自引:0,他引:1
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Mitochondrial 2-enoyl-CoA reductase from bovine liver was purified and characterized. A simple three-step purification was developed, involving ion-exchange chromatography to separate the bulk of the NADPH-dependent 2,4-dienoyl-CoA reductase, followed by chromatography on Blue Sepharose and adenosine 2',5'-bisphosphate-Sepharose. Homogeneous enzyme with a subunit Mr of 35 500 is obtained in 35% yield. The Mr of the native enzyme, determined by three different methods, yielded values that suggest that the enzyme is dimeric. NADPH is required as cofactor, and cannot be replaced by NADH. The activity of the purified enzyme towards 2-trans-double bonds in 2-monoene and 2,4-diene structures was investigated. 2-Enoyl-CoA reductase reduced the double bonds in a series of 2-trans-monoenoyl-CoA esters with different chain lengths, but did not exhibit significant activity towards 2-trans-double bonds of 2,4-dienoyl-CoA esters. This result is discussed in the light of analogous observations with enoyl-CoA hydratase. 相似文献
62.
Evidence for a rate-limiting role of cysteinesulfinate decarboxylase activity in taurine biosynthesis in vivo 总被引:1,自引:0,他引:1
J de la Rosa M H Stipanuk 《Comparative biochemistry and physiology. B, Comparative biochemistry》1985,81(3):565-571
The relationship between activities of enzymes involved in cysteine oxidation and the apparent conversion of cysteine to taurine in vivo were investigated in the rat and cat. Both hepatic cysteinesulfinate decarboxylase activity and the oxidation in vivo of cysteine to taurine were lower in the kitten than in the adult female rat and lower in the latter than in the young male rat. Our data support the hypothesis that cysteinesulfinate decarboxylase plays a rate-limiting role in taurine biosynthesis. 相似文献
63.
64.
Variants within the yeast Ty sequence family encode a class of structurally conserved proteins. 总被引:10,自引:3,他引:7
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A M Fulton J Mellor M J Dobson J Chester J R Warmington K J Indge S G Oliver P de la Paz W Wilson A J Kingsman 《Nucleic acids research》1985,13(11):4097-4112
The Ty transposable elements of Saccharomyces cerevisiae form a heterogeneous family within which two broad structural classes (I and II) exist. The two classes differ by two large substitutions and many restriction sites. We show that, like class I elements a class II element, Tyl-17, also appears to contain at least two major protein coding regions, designated TYA and TYB, and the organisational relationship of these regions has been conserved. The TYA genes of both classes encode proteins, designated p1 proteins, with an approximate molecular weight of 50 Kd and, despite considerable variation between the TYA regions at the DNA level, the structures of these proteins are remarkably similar. These observations strongly suggest that the p1 proteins of Ty elements are functionally significant and that they have been subject to selection. 相似文献
65.
Comparative Characterization of Glutamate Decarboxylase in Crude Homogenates of Oviduct, Ovary, and Hypothalamus 总被引:2,自引:2,他引:0
Some biochemical characteristics of L-glutamate decarboxylase (GAD) were compared using crude homogenates of the rat oviduct, ovary, and hypothalamus. As estimated by the measurement of CO2 production, the specific activities of oviductal and ovarian GAD were about 10 and 3% of the hypothalamic value, respectively. Stoichiometric formation of gamma-aminobutyric acid (GABA) and CO2 from L-glutamate could be observed in oviduct and hypothalamus, while in ovarian homogenates the production of CO2 was more than nine times that of GABA. Hypothalamic and tubal GAD showed similar time course, temperature dependence, and pH dependence. The dependence on protein concentration and on exogenous cofactor supply was also similar in these two tissues. The kinetic constant for L-glutamate as a substrate was nearly the same in oviduct (1.30 mM) and hypothalamus (1.64 mM). The responsiveness of tubal and hypothalamic GAD to various inhibitors was also similar. The present findings indicate that the oviductal and the hypothalamic GAD may be identical, and they suggest a possible GABAergic innervation of the Fallopian tube. 相似文献
66.
M C Hidalgo M García G Cardenete A Sanz M de la Higuera 《Revista Espanola de Fisiología》1986,42(2):191-198
After 36% of hepatic mass removal , rainbow trout recovered its initial liver weight in 20-30 days, i.e., with a regeneration rate clearly lower than in mammals. During early regeneration process hematocrit index and hemoglobin content were slightly decreased, but both parameters rapidly reached their normal values. The evolution of both glycaemia and hepatic glycogen content supported the idea of the existence of a late regeneration wave, which, in this case, could begin at about the 20th post-operative day. 相似文献
67.
A rapid, simple and reliable combined method for G-banding mammalian and human chromosomes 总被引:4,自引:0,他引:4
A simple and reliable method for G-banding chromosomes from human and mammalian cells is described. This rapid method combines hot saline and trypsin treatments and yields high quality G-bands in both bone marrow and cultured cells. 相似文献
68.
Rita Józsa M.D. Sándor Vigh Béla Mess Andrew V. Schally 《Cell and tissue research》1986,244(3):681-685
Summary In chicken embryos of different ages and in young chickens after hatching, neural elements reacting with antibodies generated against synthetic ovine corticotropin-releasing factor (CRF) were studied by means of the peroxidase-anti-peroxidase (PAP) technique at the lightmicroscopic level. CRF-immunoreactivity was first observed in perikarya located in the periventricular part of the hypothalamus on the 14th day of the incubation period. CRF-containing neural elements were detected on the same day of incubation in the external zone of the median eminence, but not in all investigated animals. In extrahypothalamic sites, immunoreactive perikarya were demonstrable in the central gray of the mesencephalon on the 15th day of incubation. Furthermore, immunoreactive cells appeared in other brain regions such as nucleus accumbens and dorsomedial nucleus of the thalamus after hatching. The present observations provide information regarding the functional development of the hypothalamo-hypophyseal-adrenal axis in the chick embryo. 相似文献
69.
Abstract The anaerobic, Gram-positive coccus Staphylococcus aureus ssp. anaerobius and its aerobic mutant MVF-SR, when kept under anaerobic conditions, excreted coproporphyrin (mainly type III) into the medium and enriched uroporphyrin (mainly type I) within the cells.
The rate of porphyrin synthesis stayed practically unaltered when the growth medium was supplemented with 50 μ g/ml 5-aminolevulinic acid (ALA), but was significantly enhanced upon supplementation with hemin (0.5 μ g/ml). When hemin and ALA were given simultaneously, a more than two-fold increase in porphyrin production compared to normal growth medium was observed. These observations indicate a stimulation of porphyrin synthesis in S. aureus by hemin.
An as yet unidentified violet pigment with an intense red-violet fluorescence under UV light ( λ = 366 nm) was found to be present in considerable amounts in cells of S. aureus ssp. anaerobius , whereas the supernatant medium of aerobically grown cells of the mutant MVF-SR contained an equally unidentified blue, non-fluorescing pigment. 相似文献
The rate of porphyrin synthesis stayed practically unaltered when the growth medium was supplemented with 50 μ g/ml 5-aminolevulinic acid (ALA), but was significantly enhanced upon supplementation with hemin (0.5 μ g/ml). When hemin and ALA were given simultaneously, a more than two-fold increase in porphyrin production compared to normal growth medium was observed. These observations indicate a stimulation of porphyrin synthesis in S. aureus by hemin.
An as yet unidentified violet pigment with an intense red-violet fluorescence under UV light ( λ = 366 nm) was found to be present in considerable amounts in cells of S. aureus ssp. anaerobius , whereas the supernatant medium of aerobically grown cells of the mutant MVF-SR contained an equally unidentified blue, non-fluorescing pigment. 相似文献
70.
C G Francisco R Freire R Hernandez J A Salazar E Suarez G A García de la Mora J A Noguez A Acosta O Jimeno 《Steroids》1983,41(3):267-275
The synthesis of nine new esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) is described, with the esterifying acids bearing an acetylenic or olefinic function in a chain of eight or nine carbon atoms, for evaluation as long-acting contraceptive agents. 相似文献