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121.
Gaussia luciferase secreted by the copepod Gaussia princeps catalyzes the oxidation of coelenterazine to produce blue light. The primary structure of Gaussia luciferase deduced from the cDNA sequence shows two repeat sequences of 71 amino acid residues, suggesting the luciferase consists of two structural domains. Two domains in Gaussia luciferase were expressed independently in Escherichia coli cells, purified and characterized. We found that both domains have luminescence activity with coelenterazine, and the catalytic properties including luminescence spectrum, optimal pH, substrate specificity and luminescence stimulation by halogen ions (Cl−, Br− and I−) are identical to intact Gaussia luciferase. Thus, Gaussia luciferase has two catalytic domains for the luminescence reaction. 相似文献
122.
J.C. Smith R.B. Derbyshire E. Cook L. Dunthorne J. Viney S.J. Brewer H.M. Sassenfeld L.D. Bell 《Gene》1984,32(3):321-327
A 43-bp DNA duplex coding for poly(arginine) [poly(arg)] has been synthesised by modified phosphotriester procedures. It has been inserted into the BglII and BamHI restriction sites of a cloned synthetic β-urogastrone (Uro) gene, under the control of the trp promoter. Subsequent induction with 3β-indole acrylic acid produces β-Uro with a C-terminal poly(arg) fusion. The raised isoelectric point of this polypeptide fusion facilitates rapid purification by cation exchange chromatography. The C-terminal poly(arg) tail can be readily removed by treatment with carboxypeptidase B. 相似文献
123.
ATP-dependent deoxyribonuclease in Bacillus subtilis and a mutant deficient in this activity 总被引:13,自引:0,他引:13
ATP-dependent DNAse activity was measured in rec+ and several rec strains of B. subtilis 168. One of the strains (marker recE5) was found to lack this activity. The enzyme from the wild type was partially purified and some of its properties were determined. The pH optimum is 9.5. Activity is higher at 50° but inactivation occurs on standing at this temperature. The enzyme requires Mg2+ (10?2M) or Mn2+ (2·10?4M). ATP is an absolute requirement and the only other nucleoside triphosphate that can partially replace it is dATP. Lack of activity in the mutant does not seem to be due to the presence of an inhibitor. Results so far do not allow us to conclude as to whether or not the mutant produces an altered enzyme. 相似文献
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128.
R Cardinaud E Dassin F Pelletier 《Biochemical and biophysical research communications》1973,52(3):1057-1063
The preparation of subfragment HMM-S-1 of Rabbit skeletal myosin was achieved by a proteolytic digestion of myofibrils in the presence of EDTA. The product was purified on DEAE-cellulose and its characteristics were compared to those of HMM-S-1 prepared by other methods. In denaturing conditions the HMM-S-1 was shown to be fragmented into a small number of well defined polypeptides. The molecular weights of which were: 68000, 52000, 26000, 235000, 21000 and 14000 daltons. A certain degree of heterogeneity was revealed by the elution profile as well as the quantitative study of polyacrylamide gel electrophoresis. 相似文献
129.
T.G. Adelman P. Arosio J.W. Drysdale 《Biochemical and biophysical research communications》1975,63(4):1056-1062
The subunit composition of human heart and liver ferritins was examined by both sodium dodecyl sulfate gel electrophoresis and acetic acidurea gel electrophoresis. These analyses indicated that both tissues contained two subunit types of similar size but different surface charge. One subunit was common to both tissues. The implications of these findings in relation to the known heterogeneity of isoferritins are discussed, and a new model of ferritin structure is proposed. 相似文献
130.
GTPase from rod outer segments: characterization by photoaffinity labeling and tryptic peptide mapping 总被引:2,自引:0,他引:2
D J Takemoto B E Haley J Hansen O Pinkett L J Takemoto 《Biochemical and biophysical research communications》1981,102(1):341-347
The photoaffinity label [γ-32P]8-N3GTP has been used to identify GTP-binding components in highly purified preparations of GTPase from bovine rod outer segments. These preparations contain two major polypeptides of 37,000 and 39,000 daltons. In the presence of photolyzing radiation, [γ-32P]8-N3GTP is covalently attached to the 37,000 dalton polypeptide. Tryptic peptide mapping of this polypeptide indicates that it is highly related to the 39,000 dalton species that has been previously identified as a GTP-binding component. 相似文献