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1.
Isolation and characterization of two isozymes of myosin heavy chain from canine atrium 总被引:2,自引:0,他引:2
I Komuro H Tsuchimochi S Ueda M Kurabayashi Y Seko F Takaku Y Yazaki 《The Journal of biological chemistry》1986,261(10):4504-4509
To clarify the characteristics of myosin isozymes in the atrium, we fractionated two isoforms of myosin heavy chain (HC), atrial HC alpha (A-HC alpha) and HC beta (A-HC beta), from the canine heart by affinity chromatography, using monoclonal antibodies specific for HC alpha (CMA19) and HC beta (HMC50), respectively, and then compared their peptide composition and enzymatic properties with those of ventricular HC alpha (V-HC alpha) and HC beta (V-HC beta). The reactivity of these isozymes with three monoclonal antibodies revealed that there are at least three different epitopes between A-HC alpha and A-HC beta. Differences in the primary structure of A-HC alpha and A-HC beta were confirmed by one- and two-dimensional gel electrophoretic analyses of these peptides, produced by digestion with alpha-chymotrypsin and cyanogen bromide (CNBr). A-HC alpha and V-HC alpha were indistinguishable proteins, and A-HC beta was also very similar to V-HC beta. Furthermore, there were differences between A-HC alpha and A-HC beta in their Ca2+-activated ATPase activities. The ATPase activity of A-HC beta was lower than that of A-HC alpha and was similar to that of V-HC beta. We concluded that there are two different isozymes of myosin heavy chain in the atrium (A-HC alpha and A-HC beta), as well as in the ventricle (V-HC alpha and V-HC beta), and that A-HC beta is very similar to V-HC beta, the predominant form of ventricular myosin, in its molecular structure and enzymatic activity. 相似文献
2.
A Seko K Kitajima M Iwasaki S Inoue Y Inoue 《The Journal of biological chemistry》1989,264(27):15922-15929
New glycoproteins of 100-120 kDa were isolated from the unfertilized eggs of flounder, Paralichthys olivaceus. Compositionally indistinguishable glycopeptides of 6 kDa were also purified from the activated or fertilized eggs. These high and low molecular mass glycoproteins are characterized by high (about 85%) carbohydrate content. Although some heterogeneities exist in the amino acid sequences, the 6-kDa glycopeptides (decapeptides with single large N-linked glycan chains), isolated from the fertilized eggs are the repeating units of the high molecular mass glycoproteins. As judged from several distinctive features the 100-120-kDa glycoproteins are apparently major components of cortical alveoli of flounder eggs and are regarded as members of glycoproteins we have defined under the name of "hyosophorin" (Kitajima, K., Inoue, S., and Inoue, Y. (1989) Dev. Biol. 132, 544-553). Composition analysis, Smith degradation, hydrazinolysis-nitrous acid deamination, permethylation analysis, and 400-MHz 1H NMR spectroscopy provided evidence for the structure of a novel penta-antennary glycan chain attached to the repeating unit (decapeptide) of the protein core. The structure thus determined is: (Formula: see text). The presence of a unique class of carbohydrate-rich glycoproteins (H-hyosophorin) in the unfertilized eggs, their conversion to the repeating unit (L-hyosophorin) at fertilization, and the finding of a free glycan chain that was formed by scission between the GlcNAc and Asn residues of L-hyosophorin, in the fertilized eggs including embryos of 4-11-h postinsemination, support the view that these molecules may be important in fertilization and subsequent development. 相似文献
3.
Yuichiro Arai Se KyungKim Hiroyasu Kinemuchi Takeshi Tadano Shinetsu Satoh Nobunori Satoh Katsuyuki Oyama Kensuke Kisara 《Neurochemistry international》1990,17(4):587-592
The present study was carried out mainly to clarify whether the two amphetamine metabolites, p-hydroxyamphetamine (P-OHA) and p-hydroxynorephedrine (p-OHN) are taken up by mouse brain 5-hydroxytryptamine (5-HT) nerve terminals to inhibit type A monoamine oxidase (MAO-A) and then potentiate the abnormal behavior, head-twitch. Of the two metabolites, only intracerebroventricular p-OHA, at 80 μg/mouse, sufficient to cause a head-twitch response (HTR), appreciably inhibited MAO-A activity without affecting MAO-B activity in homogenates of the mouse striatum, hypothalamus and the rest of the forebrain; and p-OHN did not inhibit either type of MAO at the dose tested. Estimation of intra- and extrasynaptosomal MAO-A activity showed that both metabolites significantly inhibited only the intrasynaptosomal deamination of 5-HT by MAO-A with p-OHA being more potent. Taken together with our previous findings, these present results clearly indicate that p-OHA may accumulate in the 5-HT nerve terminals through the uptake system, and concomitantly inhibit MAO-A activity. These actions of p-OHA may increase intraneuronal 5-HT levels and then potentiate 5-HT release to cause interaction with the post-synaptic 5-HT receptors. 相似文献
4.
Resuscitation of Vibrio cholerae O1 strain TSI-4 from a viable but nonculturable state by heat shock 总被引:3,自引:0,他引:3
Sun Nyunt Wai Tetsuhiro Moriya Katsuhiko Kondo Hiroyasu Misumi Kazunobu Amako 《FEMS microbiology letters》1996,136(2):187-191
Abstract Vibrio cholerae strain TSI-4 was incubated in an M9 salt solution at 15 °C for more than 100 days. The plate counts showed no viable cells on day 30, but a broth culture from that day showed the growth of bacteria. However, after 35 days the bacteria entered the nonculturable state, based on the assessment of both the plate counts and broth culture. A portion of the culture was heated at 45 °C for 1 min in a water bath and subsequently plated onto a nutrient agar plate. More than 1000 colonies were recovered after this heat-shock treatment. The recovered cells showed the same chromosomal DNA pattern in the restriction map and the same outer membrane protein pattern in SDS-PAGE. Recovery of viable cells by heat-shock was achieved in cultures grown on M9 salt but not from cultures grown in phosphate-buffered saline. This suggests that the presence of NH4 Cl in the M9 salt solution may support the growth of the bacteria in a low nutrient medium, while also playing an important role in resuscitation. 相似文献
5.
Summary Transgenic cucumber (Cucumis sativus L.) plants were successfully obtained from hypocotyl explants inoculated with Agrobacterium tumefaciens, which harbored a binary vector plasmid with NOS-nptII, CaMV 35S-I-gus and CaMV 35S-hph genes. Acetosyringone enhanced the efficiency of transformation at the cut surface cells of hypocotyl explants during five days of co-cultivation. Transformed cells were more effectively selected using 20–30 mg/l hygromycin B than using 50–100 mg/l kanamycin. Shoot regeneration occurred within 4–6 wks, and 12 of 21 regenerated plantlets displayed strong GUS expression in the very young leaves. All of 8 GUS-positive R0 plants examined showed single or a few positive bands by Southern blot analysis. The expression of the CaMV 35S-I-gus gene was observed in various tissues and organs of R0 and R1 transgenic cucumber plants. 相似文献
6.
Organic-Solvent-Tolerant Bacterium Which Secretes Organic-Solvent-Stable Lipolytic Enzyme 总被引:4,自引:1,他引:3
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A bacterial strain which could be grown in a medium containing organic solvents and which could secrete lipolytic enzyme was isolated. The stability of the lipolytic activity of the supernatant of the culture increased significantly in the presence of organic solvents such as toluene, cyclohexane, ethanol, and acetone. 相似文献
7.
8.
H+-ATPase was solubilized from the tonoplast of mung bean (Vignaradiata L.) hypocotyls and purified by fast protein liquid chromatographyon a Mono Q ion-exchange column. The purified ATPase hardlycontained any phospholipid, but it did contain 10 to 15 moleculesof sterol and 25 to 30 molecules of glycolipid per ATPase molecule,and it had little activity without exogenously added phospholipids.Each individual polar head group, acylglyceride and fatty acidthat constituted a phospholipid was incapable by itself of activatingthe ATPase. Sterols and cerebroside had little activating effect.Maximal activation of ATPase was noted with asolectin or variousmolecular species of phosphatidylcholine (PC) at 0.005% to 0.01%(w/v). The activation by the various molecular species of PCwas dependent on the length and degree of unsaturation of fattyacyl chains. PC with two saturated and long fatty acyl chainsof more than 18 carbon atoms failed entirely to activate theATPase. PC, PS and PG with 1-palmitoyl (16:0)-2-oleoyl(18:1)fatty acyl chains all activated ATPase to nearly the same extentas asolectin, but the activation by PE and PA with the samefatty acyl composition was 52% and 15% of that by asolectin,respectively. The molecular species of PC with phase-transitiontemperatures below 50C activated ATPase, as determined at 38C.The dependence on temperature of the activation by the molecularspecies of PC indicated that the activation of the ATPase beganclose to the temperature of the phase transition of the PC added.These data indicate that phospholipids in the liquid-crystallinephase are essential for the catalytic activity of the ATPase. (Received June 4, 1992; Accepted January 18, 1993) 相似文献
9.
Kenji Abe Noboru Kagei Yoshiyuki Teramura Hiroyasu Ejima 《Journal of medical primatology》1993,22(4):237-239
Hepatocellular carcinoma associated with chronic Schistosoma mansoni infection in a chimpanzee, estimated to be a 12-year-old and born in West Africa, is reported. The hepatic tumor appeared as a solitary firm nodule, and histological examination revealed well-differentiated hepatocellular carcinoma with a trabecular pattern. Hepatitis B virus and hepatitis C virus infections were excluded by serological testing in that animal. This is the first report of hepatocellular carcinoma in the chimpanzee with schistosomiasis. 相似文献
10.
Hiroyasu Kitashiba Takayoshi Iwai Kinya Toriyama Masao Watanabe Kokichi Hinata 《Sexual plant reproduction》1996,9(3):186-188
The vegetative-to-floral transition ofBrassica campestris cv. Osome was induced by vernalization. Poly(A)+RNA was isolated from the transition shoot apex after 6 weeks of vernalization, the floral apex after 12 weeks of vernalization and the expanded leaves just before vernalization, and cDNAs were synthesized. These cDNAs were used for subtraction and differential screening to select cDNA preferentially present in the transition and floral apices. Nucleotide sequences of the resulting 14 cDNA clones were determined, and northern blot analysis was carried out on six cDNAs. Two cDNA clones which did not show significant similarity to known genes were shown to be preferentially expressed in the floral apex. 相似文献