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Specific receptors for thromboxane A2 in cultured vascular smooth muscle cells of rat aorta 总被引:1,自引:0,他引:1
K Hanasaki K Nakano H Kasai H Arita K Ohtani M Doteuchi 《Biochemical and biophysical research communications》1988,150(3):1170-1175
The specific binding site for thromboxane A2 (TXA2) was studied in cultured vascular smooth muscle cells (VSMC) of the rat aorta. [3H]SQ29,548, a potent and selective TXA2 receptor antagonist, displayed high-affinity and specificity, as well as saturable and displaceable binding to rat VSMC in culture. Scatchard analysis of equilibrium binding at 24 degrees C revealed a single class of binding sites with a Kd of 1.7 nM and a Bmax of 8.0 fmol/10(6) cells. A series of TXA2 receptor antagonists completely suppressed [3H]SQ29,548 binding to rat VSMC, and the rank order of their inhibitory potencies (Ki) correlated well with the potencies for suppression of the U46619-induced contraction of rat thoracic aorta. These results suggest that specific binding sites for [3H]SQ29,548 represent the TXA2 receptor in rat VSMC. 相似文献
3.
Temperature effect of the photocyle of sensory rhodopsin (sR) was studied by nanosecond spectroscopy. Though the formation yield of sRM (sR370) was sharply decreased with temperature, those of sRK (sR680) and sRL were insensitive to temperature changes. These results show the existence of the branching process back to sR from sRL. The absorption maxima for sRK and sRL were 595 ± 5 and 555 ± 15 nm, respectively. 相似文献
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A novel complex mutation in the LDL receptor gene probably caused by the simultaneous occurrence of deletion and insertion in the same region 总被引:3,自引:0,他引:3
Kimiko Yamakawa-Kobayashi Tsutomu Kobayashi Hisako Yanagi Yae Shimakura Juichi Satoh Hideo Hamaguchi 《Human genetics》1994,93(6):625-628
A novel complex mutation with the presence of both deletion and insertion in very close proximity in the same region was detected in exon 8 of the LDL receptor gene from two apparently unrelated Japanese families with familial hypercholesterolemia (FH). In this mutant LDL receptor gene, the nine bases from nucleotide (nt) 1115 to nt 1123 (AGGGTGGCT) were replaced by six different bases (CACTGA), and consequently the four amino acids from codon 351 to 354, Glu-Gly-Gly-Tyr, were replaced by three amino acids, Ala-Leu-Asn, in the conserved amino acid region of the growth factor repeat B of the LDL receptor. The nature of the amino acid substitution and data on the families suggest that this mutation is very likely to affect the LDL receptor function and cause FH. The generation of this complex mutation can be explained by the simultaneous occurrence of deletion and insertion through the formation of a hairpin-loop structure mediated by inverted repeat sequences. Thus this mutation supports the hypothesis that inverted repeat sequences influence the stability of a given gene and promote human gene mutations. 相似文献
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Kazuo Sakamoto Kazuhiro Fujita Kimiko Hirayae Kumiko Iida Takashi Koyano Yoshihisa Asada Tsutomu Furuya 《Biotechnology Techniques》1993,7(10):749-754
Summary An integrated system has been constructed to instantly identify and efficiently sort the heterokaryons formed by plant protoplast fusion. The system is composed of the following functions: a) a transport system, b) an electro-manipulator, c) a cell harvester, d) a flow cytometer/cell sorter, and e) a control device. The conditions for an efficient and reproducible enrichment of the heterokaryons have been investigated by this system using the fluorescein isothiocyanate stained protoplasts preparing from Glycyrrhiza glabra cell cultures and unstained protoplasts of Abrus precatorius cell cultures which contain a large quantity of chlorophyll.Abbreviations MS
Murashige and Skoog (1962)
- 2,4-D
2, 4-dichlorophenoxyacetic acid
- NAA
1-naphthaleneacetic acid
- BAP
6-benzylaminopurine
- ABA
abscissic acid
- FITC
fluorescein isothiocyanate
This paper is part 96 in the series Studies on Plant Tissue Cultures. For part 95 see Orinara Y., Noguchi T. and Furuya T. (1993) submitted for publication. 相似文献
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Crosslinked polystyrene resins containing a low level of either basic or acidic groups were used for supports of alpha-chymotrypsin (CT), which catalyzed the transesterification of N-acetyl-L-phenylalanine ethyl ester (AcPheOEt) with propanol in toluene. With a minimal amount of water, CT was sorbed to the resins, basic or acidic groups of which were partly or fully neutralized by several soluble acids or bases. With an increasing degree of neutralization of basic resins by free acids, the rate of disappearance of AcPheOEt was decreased, whereas the by-product formation of AcPheOH, due to hydrolysis, was considerably suppressed, compared with the ester-exchange product, AcPheOPr. The pK(a) value of the neutralizing acid was also important for both CT activity and reaction selectivity. AcPheOPr was selectively produced at a certain range of pK(a) values. On the other hand, the neutralization of acidic resins with free amines enhanced the CT activity but a strong base promoted the formation of hydrolysis product. (c) 1995 John Wiley & Sons, Inc. 相似文献
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