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91.
A particulate fraction obtained from Alcaligenes faecalis could desaturate palmitic acid to palmitoleic acid. NADPH, ATP, CoA, Fe2+ and Mg2+ were essential cofactors for the reaction. The desaturation showed an absolute requirement for O2. Metal ions like Mn2+, Mo6+ and Cu2+ did not affect the desaturation, while Zn2+ was inhibitory. Sulfhydryl agents such as cysteine, glutathione and beta-mercaptoethanol had no effect, but SH-blocking agents like HgCl2 and p-hydroxymercuribenzoate inhibited the reaction. Azide and cyanide strongly inhibited the reaction while CO had no effect. The presence of a b-type cytochrome in the enzyme preparation was confirmed by the spectral studies on the reaction of enzyme with NADPH. Involvement of b-type cytochrome in the desaturation reaction was demonstrated by the reoxidation of b-type cytochrome initially reduced with NADPH, by the addition of palmitic acid and other cofactors. The pH optimum for the enzyme activity was 7.4. The optimum temperature for enzyme activity was 25 degrees C and maximum activity was obtained at the end of 45 min. 相似文献
92.
The autocatalytic activation of the proenzyme form of the Cls subunit of the first component of complement is reported for the first time. Incubation of the purified proenzyme at 37° and pH 7.4 results in the evolution of esterolytic activity according to a second-order autocatalytic rate law. The lag phase portion of the sigmoidal activation curve can be shortened either by increasing the proenzyme concentration or by addition of the activated Cls subunit. 相似文献
93.
Anil G. Palekar Suresh S. Tate Alton Meister 《Biochemical and biophysical research communications》1975,62(3):651-657
After rats were injected with the convulsant methionine sulfoximine, there was a rapid decrease in the glutathione concentrations of the kidney and liver, but there was no measurable effect (within 5 hours) on brain glutathione. The maximum decreases in the glutathione concentrations of kidney and liver were observed 1 hr after injection and were about 60 and 40%, respectively, of the control levels. The findings suggest that there may be at least two pools of tissue glutathione. Studies in which other amino acids were injected, and earlier studies, are consistent with the conclusion that methionine sulfoximine affects glutathione synthesis by inhibiting γ-glutamylcysteine synthetase. Injection of glycylglycine also decreased glutathione levels, an effect probably mediated by γ-glutamyltranspeptidase. 相似文献
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95.
Abstract The syntheses of three classes of adenosine analogues involving cyclosubstitution at the 6-position and functionalization at the 2-position are reported. The target molecules synthesized are stable with respect to hydrolytic deamination by mammalian adenosine deaminase, and, because of major structural changes at the 2- and 6-positions, these compounds are expected to be poor phosphorylation substrates for the kinases. Adenosine receptor binding data reveal that several of the compounds synthesized show excellent A1 receptor affinity and A2/A1 selectivity. 相似文献
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97.
Jessica Voisin Francesca Farina Swati Naphade Morgane Fontaine Kizito‐Tshitoko Tshilenge Carlos Galicia Aguirre Alejandro Lopez‐Ramirez Julia Dancourt Aurélie Ginisty Satish Sasidharan Nair Kuruwitage Lakshika Madushani Ningzhe Zhang Fran?ois‐Xavier Lejeune Marc Verny Judith Campisi Lisa M. Ellerby Christian Neri 《Aging cell》2020,19(11)
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99.
Nanobiotechnology provides novel set of tools to manipulate and enhance crop production using nanoparticles, nanofibres, nanoemulsions, and nanocapsules. Nanomaterials provide a platform to deliver agrochemicals and various macromolecules needed for plant growth enhancement and resistance to stresses. Smart delivery of agrochemicals increases the yield by optimizing water and nutrient conditions. Another added advantage is controlled release and site-directed delivery of agrochemicals. Further enhancement in quality and quantity in agriculture can be achieved by nanoparticle-mediated gene transformation and delivery of macromolecules that induces gene expression in plants. Various types of nanomaterials have been tested so far and the results have been promising in terms of productivity and quality enhancement. 相似文献
100.
Kshirsagar Parthraj R. Mohite Ashwini Suryawanshi Suresh Chavan Jaykumar J. Gaikwad Nikhil B. Bapat Vishwas A. 《Plant Cell, Tissue and Organ Culture》2021,144(2):383-396
Plant Cell, Tissue and Organ Culture (PCTOC) - The present study reports an optimized protocol for high frequency in vitro plant propagation through direct and indirect organogenesis, phytochemical... 相似文献