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21.
22.
Inka Brockhausen Arthur A Grey Henrianna Pang Harry Schachter Jeremy P Carver 《Glycoconjugate journal》1988,5(4):419-448
Sixteen asparagine-linked oligosaccharides ranging in size from (Man)2(GlcNAc)2 (Fuc)1 to (GlcNAc)6(Man)3(GlcNAc)2 were obtained from human 1-acid glycoprotein and fibrinogen, hen ovomucoid and ovalbumin, and bovine fetuin, fibrin and thyroglobulin by hydrazinolysis, mild acid hydrolysis and glycosidase treatment. The oligosaccharides hadN-acetylglucosamine at the reducing termini and mannose andN-acetylglucosamine residues at the non-reducing termini and were prepared for use asN-acetylglucosaminyltransferase substrates. Purification of the oligosaccharides involved gel filtration and high performance liquid chromatography on reverse phase and amine-bonded silica columns. Structures were determined by 360 MHz and 500 MHz proton nuclear magnetic resonance spectroscopy, fast atom bombardment-mass spectrometry and methylation analysis. Several of these oligosaccharides have not previously been well characterized.Abbreviations bis
bisecting GlcNAc
- DMSO
dimethylsulfoxide
- FAB
fast atom bombardment
- Fuc
l-fucose
- Gal
d-galactose
- GLC
gas-liquid chromatography
- GlcNAc or Gn
N-acetyl-d-glucosamine
- HPLC
high performance liquid chromatography
- Man or M
d-mannose
- MES
2-(N-morpholino)ethanesulfonate
- MS
mass spectrometry
- NMR
nuclear magnetic resonance
- PIPES
piperazine-N,N-bis(2-ethane sulfonic acid)
the nomenclature of the oligosaccharides is shown in Table 1. 相似文献
23.
24.
Two analogues of angiotensin III were compared as antagonists of the pressor response to angiotensin II (ANG II) and angiotensin III (ANG III) in conscious, unrestrained rats. Dose-mean arterial pressure (MAP) response curves were obtained for ANG II and ANG III in the absence or presence of [Ile7]ANG III (1.3 x 10(-7) mol/kg) or [Sar1 Ile7]ANG III (1.2 x 10(-7) mol/kg). In the presence of [Ile7]ANG III, the dose-MAP response curves for ANG II and ANG III were significantly displaced to the right. [Ile7]ANG III behaved as a partial agonist on ANG II but not ANG III receptors. In the presence of [Sar1 Ile7]ANG III, the dose-MAP response curve for ANG III but not ANG II was significantly displaced to the right. This suggests that [Sar1 Ile7]ANG III is a selective antagonist of ANG III in the vasculature. [Ile7]ANG III, on the other hand, antagonizes both ANG II and ANG III receptors. Our results support the hypothesis of the existence of a sub-class of angiotensin receptors activated by ANG III in the vascular smooth muscle. 相似文献
25.
Cibacron blue T_3GA与溴化氰活化的Sepharose 4B偶联后,产生一种能有效地分离有机磷水解酶的吸附剂。用0.15mol/L MgCl_2溶液从黄杆菌P3—2细胞抽提出的粗酶液通过柱层析分离,即可得到纯化8倍、酶活性回收率为269.4%的纯酶制品。该酶制品用凝胶电泳测是均一的。 相似文献
26.
27.
Rong-Xiang Fang Zhen Pang Dong-Ming Gao Ke-Qiang Mang Nam-Hai Chua 《Plant molecular biology》1991,17(6):1255-1257
28.
The prokaryotic ribosomal operon, str, contains open reading frames for the two elongation factors, elongation factor G (EF-G) and elongation factor Tu (EF-Tu), and ribosomal proteins S7 and S12. The DNA sequence and predicted amino acid sequence for S7 from Chlamydia trachomatis are presented and compared with homologues from other prokaryotes. Also, the relationship of the S7 gene to the open reading frames for ribosomal protein S12 and EF-G is described. Significant amino acid homology is also noted when the amino-terminal sequence of chlamydial EF-G is compared with the cytoplasmic tetracycline resistance factors, tetM and tetO, from streptococci and Campylobacter jejuni. Related findings and possible resistance mechanisms for the newly recognized tetracycline-resistant clinical isolates of C. trachomatis are discussed. 相似文献
29.
“缺体回交法”选育普通小麦—山羊草异代换系的研究 总被引:3,自引:2,他引:1
利用从兰单体自交分离得到的5个自花结实的4D缺体小麦(映72180、块天选15等)作母本与11个山羊草(Ae.speltoides, Ae.sharonensis等)杂交,再以4D缺体为轮回亲本对杂种进行回交,借助于幼胚培养技术,获得了缺天选15×拟斯卑尔脱山羊草二体异代换系,缺72180×沙融山羊草单体异代换系。代换系生长发育良好,育性基本正常,表明山羊草的4S染色体能够补偿小麦缺失的4D染色体的功能。证明利用“缺体回交法”选育普通小麦—山羊草异代换系是有效的和可行的。 相似文献
30.