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751.
Bovine brain calmodulin (B-CaM) was shown to inhibit the native Tetrahymena calmodulin (T-CaM)-dependent activation of guanylate cyclase in Tetrahymena at the concentrations that failed to affect the basal enzyme activity. The enzyme inhibition was completely reversed by high concentration of T-CaM, but not by Ca2+. The antagonistic interaction between T-CaM and B-CaM was not observed in the calmodulin-dependent cyclic nucleotide phosphodiesterase from bovine brain. Two calmodulins migrated independently on 15% polyacrylamide gel system. These results suggest that B-CaM exerts its inhibitory effect on the guanylate cyclase activation by interacting with the calmodulin-binding site of this enzyme. 相似文献
752.
Daniele Zendrini Rechenchoski Ligia Carla Faccin-Galhardi Rosa Elisa Carvalho Linhares Carlos Nozawa 《Folia microbiologica》2017,62(2):151-156
Herpes simplex virus (HSV) infections are common and widespread; nevertheless, their outcome can be of unpredictable prognosis in neonates and in immunosuppressed patients. Anti-HSV therapy is effective, but the emergence of drug-resistant strains or the drug toxicity that hamper the treatment is of great concern. Vaccine has not yet shown relevant benefit; therefore, palliative prophylactic measures have been adopted to prevent diseases. This short review proposes to present concisely the history of HSV, its taxonomy, physical structure, and replication and to explore the pathogenesis of the infection, clinical manifestations, laboratory diagnosis, treatment, prophylaxis and epidemiology of the diseases. 相似文献
753.
S Nakashima H Hattori L Shirato A Takenaka Y Nozawa 《Biochemical and biophysical research communications》1987,148(3):971-978
Human platelets labeled with [3H]arachidonic acid and permeabilized with saponin produced [3H]1,2-diacylglycerol (DG) by phospholipase C and released [3H]arachidonate by phospholipase A2, when activated with thrombin. Thrombin-induced arachidonate liberation was almost completely inhibited with pretreatment of pertussis toxin (10 micrograms/ml), whereas DG formation was decreased by only 20-40% in the toxin-treated platelets. Although guanosine 5'-o-(2-thiodiphosphate) (GDP beta S) suppressed arachidonate release and DG production in a dose-dependent manner, the half maximal inhibition required less than 10 microM for arachidonate release but more than 100 microM for DG production. Moreover, the dose-response effects of NaF on arachidonate release and DG formation were different. These results indicate that arachidonate release and DG formation are differently affected by these agents acting on guanine nucleotide binding proteins (G-proteins), suggesting that the distinct G proteins modulate the activity of phospholipase C and phospholipase A2. 相似文献
754.
K Takamatsu M Mikami K Kiguchi S Nozawa M Iwamori 《Biochimica et biophysica acta》1992,1165(2):177-182
In human cervical epithelium, uterine endometrium, and mucosa of the fallopian tubes, neutral glycosphingolipids were exclusively represented by the globo-series glycosphingolipids, such as CMH, LacCer, Gb3Cer and Gb4Cer, but the molecular species of their ceramide moieties were characteristically altered in the cervical epithelium and uterine endometrium during the menstrual cycle. Individual neutral glycosphingolipids in the cervical epithelium and the uterine endometrium at the follicular phase gave two bands on TLC, whereas those at the luteal phase displayed three bands, the third being the lower migrating one. Neutral glycosphingolipids migrating to the same positions as these lower-migrating bands were constantly detected in the mucosa of the fallopian tubes, independent of the menstrual cycle. The lower-migrating bands for the cervical epithelium and the uterine endometrium at the luteal phase were due to molecules mainly constructed of phytosphingosine with alpha-hydroxy fatty acids having chain lengths of 18-24 and 4-sphingenine with alpha-hydroxy fatty acids having chain lengths of 16-22, whereas those in the mucosa of the fallopian tubes were exclusively N-alpha-hydroxypalmitoyl 4-sphingenine. 相似文献
755.
Purification and characterization of lysophospholipase-transacylase of pathogenic fungus Candida albicans 总被引:1,自引:0,他引:1
A lysophospholipase-transacylase was purified to homogeneity from the culture broth of Candida albicans by ammonium sulfate precipitation and chromatographs on DEAE-cellulose, Ultrogel AcA-44, first Mono Q, hydroxyapatite, TSKgel-3000 and second Mono Q columns. The purified protein was a single band (Mr 41,000) as inferred by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It had a specific activity of 78 mumol/min per mg protein for fatty acid release and 320 mumol/min per mg protein for phosphatidylcholine formation. Fatty acid release obeyed Michaelis-Menten kinetics and the apparent Km was 76 microM of 1-palmitoyl-sn-glycero-3-phosphatidylcholine, but Lineweaver-Burk plots of transacylase activity was parabolic. The ratio of hydrolase to transacylase activity of the purified enzyme was varied depending upon the concentration of lysophosphatidylcholine. Transacylation was prominent at high concentration of substrate and the ratio of hydrolase to transacylase was 0.24. Low concentration of palmitoylcarnitine (50 microM) inhibited markedly phosphatidylcholine formation but stimulated fatty acid release. The degree of esterification of 1-acyllysophosphatidylcholine was altered with mixtures of different molecular species of substrate, demonstrating acyl chain selectivity in the transfer process. These results suggest that C. albicans lysophospholipase-transacylase is different from the corresponding mammalian enzymes in enzymatic properties. 相似文献
756.
S. Takaichi Zheng-Yu Wang Mitsuo Umetsu Tsunenori Nozawa Keizo Shimada Michael T. Madigan 《Archives of microbiology》1997,168(4):270-276
The complete carotenoid composition of the thermophilic green sulfur bacterium Chlorobium tepidum strain TNO was determined by spectroscopic methods. Major carotenoids were four kinds of carotenes: γ-carotene, chlorobactene,
and their 1′,2′-dihydro derivatives (1′,2′-dihydro-γ-carotene and 1′,2′-dihydrochlorobactene). In lesser amounts, hydroxyl
γ-carotene, hydroxyl chlorobactene, and their glucoside fatty acid esters were found. The only esterified fatty acid present
was laurate, and OH-chlorobactene glucoside laurate is a novel carotenoid. In other strains of C. tepidum, the same carotenoids were found, but the composition varied from strain to strain. The overall pigment composition in cells
of strain TNO was 4 mol carotenoids and 40 mol bacteriochlorophyll c per mol bacteriochlorophyll a. The effects of nicotine on carotenoid biosynthesis in C. tepidum differed from those in the thermophilic green nonsulfur bacterium Chloroflexus aurantiacus.
Received: 3 February 1997 / Accepted: 6 June 1997 相似文献