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1.
The effects of histone 2A and some polycations on microsomal carbamylphosphate:D-glucose phosphotransferase and glucose-6-phosphate phosphohydrolase activities (D-glucose-6-phosphate phosphohydrolase, EC 3.1.3.9), have been investigated. 1. Histone 2A and polycations activate the two enzymic activities. At a constant cation concentration, this activation increases with the number of cationic groups per molecule. 2. Activation by histone 2A is related to its fixation on microsomal membranes. This fixation varies with quantities of histones and pH. 3. The nature of the interactions between histones and microsomal membranes is shown to be electrostatic, probably between the cationic groups of histones and the anionic group of membranous lipids. 4. Kinetic analysis reveal that histone 2A increases the maximal reaction velocity but does not affect the apparent Michaelis constant values for the substrates. 5. The role played by the cationic groups of histone 2A on the microsomal glucose 6-phosphatase, is discussed. 相似文献
2.
3.
A DNA base analogue, 5-bromodeoxyuridine (BUdR), promoted floweringof Arabidopsis thaliana in short and long photoperiods and evenin total darkness. The promotive effect of BUdR was nullifiedby thymidine which had a weak inhibitory effect by itself. AnotherDNA base analogue, 5-fluorodeoxyuridine (FUdR), inhibited theflowering at a low concentration (108 M), but markedlyenhanced the promotive effect of BUdR if they were present togetherin the culture medium. In the flower-promoting medium containing both BUdR and FUdR,the number of acid phosphatase isozymes decreased temporarily,followed by an increase to the control level with a prolongedculture period. The number of peroxidase isozymes was greaterin plants grown in the medium with BUdR or BUdR $ FUdR thanin those without them. (Received October 22, 1987; Accepted March 25, 1988) 相似文献
4.
Structural proteins and the characteristics of infectious flacherie virus (IFV) purified from the silkworm, Bombyx mori, are described. The purified IFV had four major structural proteins, which were detected only in high concentration gels of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and a few minor ones. Molecular weights of the major proteins were 35,200 (VP 1), 33,000 (VP 2), 31,200 (VP 3), and 11,600 (VP 4), and numbers per virion were 62, 57, 54, and 31, respectively. Amino acid compositions of VP 1, VP 2, and VP 3 were similar to each other but that of VP 4 was somewhat different. By isoelectric focusing and two-dimensional electrophoresis, high resolution of the structural proteins was obtained with silver staining. The isoelectric points of the four major proteins were determined as 7.7(VP 1), 6.7(VP 2), 4.8(VP 3), and 5.5(VP 4). This work is the first report on insect picornaviruses that presents some discriminative properties of each viral protein that was compared to those of mammalian picornaviruses. 相似文献
5.
Transductional Analysis of the leu-thr Region of Chromosome of Serratia marcescens 总被引:2,自引:0,他引:2
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Transductional analysis of the chromosomal linkage map of Serratia marcescens near leu revealed the following order of loci: ser4-thr3-pyr1-pdx2-leu1-azi8. 相似文献
6.
Possible Involvement of Abscisic Acid in Increases in Activities of Two Vacuolar H+-Pumps in Barley Roots under Aluminum Stress 总被引:1,自引:0,他引:1
Kasai Minobu; Sasaki Masao; Tanakamaru Shigemi; Yamamoto Yoko; Matsumoto Hideaki 《Plant & cell physiology》1993,34(8):1335-1338
Levels of abscisic acid (ABA) in barley roots increased upontreatment with AlCl3. Treatment with AlCl3 or ABA increasedboth ATP-dependent and PPi-dependent H+-pumping activities intonoplast-enriched membrane vesicles. Increase in the H+-pumpingactivities caused by aluminum stress could result from increasedlevels of ABA.
1Present address: Department of Botany, Faculty of Science,Hirosaki University, Hirosaki, Aomori, 036 Japan 相似文献
7.
Shinichi Yoshida Saori Yonehara Shigemi Minami Hyo-cheol Ha Kenji Iwahara Takashi Watanabe Yoichi Honda Masaaki Kuwahara 《Mycoscience》1996,37(4):417-425
Manganese peroxidase (MnP) and lignin peroxidase (LiP) were produced by growing a white-rot fungusBjerkandera adusta statically, on a wood meal/wheat bran culture in flasks. MnP and LiP reached their maximum activity after 6 and 19 days of
inoculation, respectively. Both MnP and LiP are thought to be important enzymes in lignin biodegradation byB. adusta. Ion exchange chromatography showed thatB. adusta produced a single LiP and a single MnP enzyme in wood meal/wheat bran culture. These enzymes were separated and characterized.
The molecular weight of MnP was 46,500 with a pl of 3.9. The molecular weight of LiP was estimated to be 47,000 with a pl of 3.5. Spectral analysis demonstrated that both enzymes are heme proteins. Production of these enzymes was also achieved
using a rotarysolid culture fermenter. MnP, LiP and veratryl alcohol oxidase were produced byB. adusta in the fermenter. 相似文献
8.
A polyclonal antiserum was raised against highly purified RNA polymerase II from soybean embryos. Pure RNA polymerase II was fractionated on sodium dodecyl sulfate-polyacrylamide gels and transferred onto nitrocellulose sheets, incubated with the immune antiserum and then with iodinated protein A. Autoradiograms showed that the immune antiserum recognized all subunits of RNA polymerase II. Subunits 42, 27 and 16 kdalton were particularly reactive. Application of this transfer technique to protein extracts from soybean embryos or from cultured soybean cells allowed the identification of subunits of RNA polymerase II in the extracts. Analysis of the staining of the bands on the autoradiograms for increasing amounts of pure RNA polymerase II demonstrated that the transfer was quantitative, so that standard curves could be drawn to estimate the unknown amounts of enzyme in the extracts.Abbreviations DEAE
diethylaminoethyl
- SDS
sodium dodecyl sulfate 相似文献
9.
Hypocotyl sections with and without the cotyledons were cutfrom bean seedlings and incubated under white light of 6000lux. The cotyledons had an inhibitory effect as well as a promotiveeffect on hypocotyl growth. The former effect was more strikingin the dwarf variety, and the latter in the tall variety. Whenthe hypocotyl units were exposed to light for shorter times(6 hr or less) or incubated under weaker light (1600 and 50lux), the inhibitory effect of the cotyledons decreased greatly,and in the tall variety the presence of cotyledons producedno inhibition, but a promotion of hypocotyl growth. GA treatmentenhanced hypocotyl growth and counteracted the growth inhibitioncaused by the cotyledons. On the whole, the GA effect was moremarked in the tall variety than in the dwarf. The elongation of bean hypocotyls may be controlled by a balancebetween the inhibitory and promotive effects of cotyledons,and the predominance of the former over the latter may be oneof the causes for expressing dwarfing. (Received November 13, 1976; ) 相似文献
10.
The choice of a suitable detergent for solubilization of UDPglucose-ceramide glucosyltransferase from Golgi membranes has been investigated. Among the various classes of detergent, CHAPS, a zwitterionic detergent, was used as it produced a substantial activation of the enzyme activity. 30% of the enzyme activity and 50% of proteins were solubilized in the first attempts. Further experiments were conducted with addition of a second detergent, Zwittergent 3-14 which increased enzyme recovery to 45%. Lastly, reducing the concentrations of buffer and divalent cations Mn2+, Mg2+ and introducing glycerol (20%, v/v) allowed 80% of proteins to be solubilized together with 68% of the ceramide glucosyltransferase activity. 相似文献