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11.
Hirofumi Ogawa Yoshihisa Ishiguro Motoji Fujioka 《Archives of biochemistry and biophysics》1983,226(1):265-275
Guanidoacetate methyltransferase (EC 2.1.1.2) has been purified about 800-fold from rat liver. The purified preparation shows a single protein band on polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate. The molecular weight of the enzyme is estimated to be 25,000 and 26,000 by Sephadex gel molecular-exclusion chromatography and by electrophoresis in polyacrylamide gradient gel, respectively. The sodium dodecyl sulfate-denatured enzyme also has a molecular weight of 26,000; thus, the enzyme is a monomeric protein. Guanidoacetate methyltransferase as isolated is catalytically inactive, but is readily reactivated by incubation with a thiol. The reactivated enzyme, which contains 3 mol of sulfhydryl groups/mol of enzyme, is again inactivated by oxidized glutathione. This inactivation is accompanied by the disappearance of two sulfhydryl residues. The relationship between the loss of enzyme activity and the number of residues disappeared indicates that the integrity of these sulfhydryl residues is critical for activity. The oxidized enzyme fails to bind the substrate S-adenosylmethionine as evidenced by the equilibrium dialysis study. Alkylation of the nonoxidizable sulfhydryl by N-ethylmaleimide shows that this residue is also essential for activity. UV absorption, fluorescence, and CD spectra show no difference between the reduced and oxidized enzymes, but the former is more susceptible to proteolytic attack by trypsin. The enzyme has an isoelectric pH of 5.3, and is most active at pH 9.0. From the CD spectrum, an α helix content of 15% is calculated. The Km values for guanidoacetate and S-adenosylmethionine are 97.5 and 6.73 μm, respectively, at pH 8.0 and 37 °C. 相似文献
12.
Saccharopine [?-N-(l-glutaryl-2)-l-lysine] has been found to occur in normal, untreated mouse liver. The pool of saccharopine as well as that of α-aminoadipate become labeled shortly after the administration of l-lysine-U-14C into intact mouse. In vitro experiments using the mouse liver homogenate have shown that l-lysine is converted to saccharopine in the presence of α-ketoglutarate and NADPH, and saccharopine to α-aminoadipate in the presence of NAD+. The oxidation of α-aminoadipic-δ-semialdehyde (Δ1-piperideine-6-carboxylate), the proposed reaction product of saccharopine cleavage, to α-aminoadipate is effected by either NAD+ or NADP+. 相似文献
13.
14.
Method for Obtaining Cleaned Putrefactive Anaerobe 3679 Spores 总被引:6,自引:1,他引:5
15.
Toshiki Hiroyoshi 《Genetics》1961,46(10):1373-1380
16.
Gibberellin A(3) Is Biosynthesized from Gibberellin A(20) via Gibberellin A(5) in Shoots of Zea mays L 总被引:11,自引:8,他引:3 下载免费PDF全文
Fujioka S Yamane H Spray CR Phinney BO Gaskin P Macmillan J Takahashi N 《Plant physiology》1990,94(1):127-131
[17-13C,3H]-Labeled gibberellin A20 (GA20), GA5, and GA1 were fed to homozygous normal (+/+), heterozygous dominant dwarf (D8/+), and homozygous dominant dwarf (D8/D8) seedlings of Zea mays L. (maize). 13C-Labeled GA29, GA8, GA5, GA1, and 3-epi-GA1, as well as unmetabolized [13C]GA20, were identified by gas chromatography-selected ion monitoring (GC-SIM) from feeds of [17-13C, 3H]GA20 to all three genotypes. 13C-Labeled GA8 and 3-epi-G1, as well as unmetabolized [13C]GA1, were identified by GC-SIM from feeds of [17-13C, 3H]GA1 to all three genotypes. From feeds of [17-13C, 3H]GA5, 13C-labeled GA3 and the GA3-isolactone, as well as unmetabolized [13C]GA5, were identified by GC-SIM from +/+ and D8/D8, and by full scan GC-MS from D8/+. No evidence was found for the metabolism of [17-13C, 3H]GA5 to [13C]GA1, either by full scan GC-mass spectrometry or by GC-SIM. The results demonstrate the presence in maize seedlings of three separate branches from GA20, as follows: (a) GA20 → GA1 → GA8; (b) GA20 → GA5 → GA3; and (c) GA20 → GA29. The in vivo biogenesis of GA3 from GA5, as well as the origin of GA5 from GA20, are conclusively established for the first time in a higher plant (maize shoots). 相似文献
17.
The term 'monogamy' represents a complex of mating systems that has been relalively neglected. Monogamy is generally associated with significant biparental care and is most common among birds. Recent work has addressed such aspects as the evolutionary incentives for (and value of) contributions by the male parent, how the distributions of females and critical nesting resources can promote monogamy, male defense of genetic paternity, the causes of long-term mate-retention in certain species, and the subtle means by which sexual selection operates within basically monogamous systems. New advances in testing genetic relatedness, especially DNA fingerprinting, promise much for the assessment of individual costs and benefits of monogamy. 相似文献
18.
Hiroyuki Suzuki Shozo Fujioka Suguru Takatsuto Takao Yokota Noboru Murofushi Akira Sakurai 《Journal of Plant Growth Regulation》1993,12(2):101-106
Feeding experiments with tritium- and deuterium-labeled castasterone (CS) were conducted with three cell lines of Catharanthus roseus, including crown gall cells and nontransformed cells. In all three cell lines, the conversion of CS to brassinolide (BL) was observed and unequivocally confirmed by gas chromatography/mass spectrometry (GC/MS). This is the first conclusive evidence that CS is the biosynthetic precursor of BL.Biosynthesis of brassinosteroids in Catharanthus roseus. Part II. Part I of this series: Yokota et al. (1990a). 相似文献
19.
Shuhei Takatsuka Takeshi Kubota Yuta Kurashina Sho Kurihara Motoki Hirabayashi Masato Fujioka Hirotaka James Okano Hiroaki Onoe 《Biotechnology and bioengineering》2023,120(8):2371-2377
Adeno-associated virus (AAV)-based gene therapy holds promise as a fundamental treatment for genetic disorders. For clinical applications, it is necessary to control AAV release timing to avoid an immune response to AAV. Here we propose an ultrasound (US)-triggered on-demand AAV release system using alginate hydrogel microbeads (AHMs) with a release enhancer. By using a centrifuge-based microdroplet shooting device, the AHMs encapsulating AAV with tungsten microparticles (W-MPs) are fabricated. Since W-MPs work as release enhancers, the AHMs have high sensitivity to the US with localized variation in acoustic impedance for improving the release of AAV. Furthermore, AHMs were coated with poly-l -lysine (PLL) to adjust the release of AAV. By applying US to the AAV encapsulating AHMs with W-MPs, the AAV was released on demand, and gene transfection to cells by AAV was confirmed without loss of AAV activity. This proposed US-triggered AAV release system expands methodological possibilities in gene therapy. 相似文献
20.
Shiro Higashi Akinori Nakashima Hideki Ozaki Mikiko Abe Toshiki Uchiumi 《Journal of plant research》1993,106(1):47-54
The process of digestion of captured feeds in a pitcher, an insect-trapping organ, ofNepenthes was studied. Changes in bacterial population, pH and NH4
+ concentrations in pitcher juice were examined. Strong activities of both acid- and alkaline phosphatase, phosphoamidase,
esterase C4 and esterase C8 were found in the pitcher juice. Optimum pH of proteases in the juice and those secreted from
bacteria showed pH 3.0 and pH 8.0–9.0, respectively. Twenty six strains of bacteria were isolated from 4 pitchers: 10 strains
were gram positive, 16 strains were gram negative (10 strains had casein hydrolase activity). A proton excretion was induced
by NH4
+ released from the added solutions, and accordingly, the pH of the solutions fell. As a simulation model of the digestion
process of feeds in pitcher juice and polypeptone solution was added into the washed pitcher. A good correlation was found
among the NH4
+ concentration, pH and bacterial cell titer. 相似文献