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91.
92.
Structure determination of a nucleoside Q precursor isolated from E. coli tRNA: 7-(aminomethyl)-7-deazaguanosine. 总被引:5,自引:3,他引:2 下载免费PDF全文
N Okada S Noguchi S Nishimura T Ohgi T Goto P F Crain J A McCloskey 《Nucleic acids research》1978,5(7):2289-2296
A precursor of modified nucleoside Q isolated from E. coli methyl-deficient tRNA was determined to be 7-(aminomethyl)-7-deazaguanosine. The structure was deduced by means of its chromatographic and electrophoretic mobilities, and UV and mass spectra, in addition to comparison with the synthesized authentic compound. The same molecule is also found in tRNA of an E. coli mutant selected for deficient synthesis of modified nucleosides. 相似文献
93.
Leukotriene A: stereochemistry and enzymatic conversion to leukotriene B 总被引:13,自引:0,他引:13
Olof Rådmark Curt Malmsten Bengt Samuelsson David A. Clark Giichi Goto Anthony Marfat E.J. Corey 《Biochemical and biophysical research communications》1980,92(3):954-961
Leukotriene A was assigned the structure 5(S)--5,6-oxido-7,9--eicosatetraenoic acid by the enzymatic conversion of a synthetic product of known stereochemistry into the naturally occurring isomer of 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid in human polymorphonuclear leukocytes. 相似文献
94.
David A. Clark Giichi Goto Anthony Marfat E.J. Corey Sven Hammarström Bengt Samuelsson 《Biochemical and biophysical research communications》1980,94(4):1133-1139
A slow reacting substance, produced by murine mastocytoma cells, has been shown to have the structure 5(S)-hydroxy-6(R)--glutathionyl-7,9,11- leukotriene C, previously referred to as leukotriene C-2) by ultraviolet spectroscopy, amino acid analyses, lipoxygenase conversion and comparisions with a synthetic compound of known structure and stereochemistry. 相似文献
95.
Four monolignol glucosides have been isolated and identified from the needles of Pinus contorta. Chavicol 4-O-α-L-arabinofuranosyl-(1 → 相似文献
96.
Formation of bile acids in hemoglobin-free perfused rat livers 总被引:1,自引:0,他引:1
97.
The structure for trichoclin, (E)-8-(3-methyl-4-hydroxy-2-butenyloxy)-psoralen, a new furocoumarin isolated from Trichocline incana, has been established. Phellopterin and isopimpinellin were also obtained. The new side chain of trichoclin was confirmed by synthesis. 相似文献
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Purification, characterization, and amino acid sequences of pepsinogens and pepsins from the esophageal mucosa of bullfrog (Rana catesbeiana) 总被引:1,自引:0,他引:1
E Yakabe M Tanji M Ichinose S Goto K Miki K Kurokawa H Ito T Kageyama K Takahashi 《The Journal of biological chemistry》1991,266(33):22436-22443
Two pepsinogens (pepsinogens 1 and 2) were purified from the esophageal mucosa of the bullfrog (Rana catesbeiana), and their molecular weights were determined to be 40,100 and 39,200, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2-terminal 70-residue sequences of both pepsinogens are the same, including the 36-residue activation segment. Furthermore, a cDNA clone encoding frog pepsinogen was obtained and sequenced, which permitted deduction of the complete amino acid sequence (368 residues) of one of the pepsinogen isozymogens. The calculated molecular weight of the protein (40,034) coincided well with the values obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results are incompatible with the previous report (Shugerman R. P., Hirschowitz, B. I., Bhown, A. S., Schrohenloher, R. E., and Spenney, J. G. (1982) J. Biol. Chem. 257, 795-798) that the major pepsinogen isolated from the bullfrog esophageal gland is a unique "mini" pepsinogen with a molecular weight of approximately 32,000-34,000. The two pepsinogens were immunologically indistinguishable from each other and related to human pepsinogen C. The deduced amino acid sequence was also more homologous with those of pepsinogens C than those of pepsinogens A and prochymosin. These results indicate that the frog pepsinogens belong to the pepsinogen C group. They were both glycoproteins, and therefore, this is the first finding of carbohydrate-containing pepsinogens C. Both pepsinogens were activated to pepsins in the same manner by an apparent one-step mechanism. The resulting pepsins were enzymatically indistinguishable from each other, and their properties resembled those of tuna pepsins. 相似文献