主题：【求助】（已应助）求助：文献 急需下面文献，麻烦大家！~谢谢！~

Simplification of complex tryptic digests for capillary electrophoresis by affinity selection of histidine-containing peptides with immobilised metal ion affinity chromatography
今天怎么不能上传附件啊？

第四篇只能查摘要
Evaluation of the interaction of peptides with Cu(II), Ni(II), and Zn(II) by high-performance immobilized metal ion affinity chromatography*1

Tai-Tung Yip, *, , Yasuo Nakagawa† and Jerker Porath‡

* USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, Texas 77030, USA
† Peptide Institute, Protein Research Foundation, 4-1-2 INA, Minoh-shi, Osaka 562, Japan
‡ Institute of Biochemistry, Biomedical Center, University of Uppsala, S-75123, Uppsala, Sweden

Received 24 March 1989.  Available online 29 November 2004.




Abstract
High-performance immobilized metal ion affinity chromatography was utilized to evaluate the adsorption properties of 67 synthetic, biologically active, peptides ranging in size from 5 to 42 residues. The metal ions, Cu(II), Ni(II) and Zn(II), were immobilized by iminodiacetic acid (IDA) coupled to TSK gel 5PW (10 μm). Two types of gradient elution (imidazole and pH) were used to evaluate peptide retention by the metal ions. A decreasing pH gradient and an increasing imidazole gradient eluted the peptides in similar order. IDA-Cu(II) and IDA-Zn(II) showed very similar selectivities for the peptides analyzed; however, IDA-Zn(II) displayed a weaker affinity for the peptides. IDA-Ni(II) showed a slightly different pattern of selectivity. Peptide adsorption effects contributed by the metal-free gel matrix were found to be relatively minor. The concentration and type of salt included in the mobile phase could affect the relative affinities of the peptides for the immobilized metal ions. Retention coefficients were assigned to individual amino acid residues by multiple linear regression analysis. Histidine showed the largest positive correlation with retention, followed by aromatic amino acid residues. Modified N-terminal residues resulted in negative contributions to retention. Analyses of peptide amino acid composition alone allowed prediction of peptide retention behavior on immobilized metal ion affinity columns.

第一篇
文章1

第四和第五好像一样啊老大

第三篇
第3篇

文章2
第二篇

nature那篇查不到了，呵呵

第6篇!
第4,5篇一样一样一样的呀!而且的确只有摘要,楼上的已经贴过了!
Nature

我声望太低了，所以每次上传东西都得等待批准，耽误了求助者的时间，大家有什么好办法让声望快速增加阿，郁闷中...