Use of an amino acid ionic liquid as an ion exchange chromatography mobile phase modifier for the analysis of magnesium, calcium, zinc, and iron ions

2018 ◽  
Vol 1 (7) ◽  
pp. 468-474 ◽  
Author(s):  
Huawei Di ◽  
Wei Liu ◽  
Qi Li ◽  
Qing Gao ◽  
Xiashi Zhu
1968 ◽  
Vol 14 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Richard P Geer ◽  
Richard K Hantman ◽  
Cyrus V Swett

Abstract Amino acid excretions of 82 individuals were quantitatively determined by ion-exchange chromatography. The results are expressed as µmoles amino acid per day, divided by milligrams α-amino acid nitrogen per day. This index is independent of age and provides a more useful method of representation than those presently employed in the literature.


1969 ◽  
Vol 52 (5) ◽  
pp. 981-984 ◽  
Author(s):  
J E Knipfel ◽  
D A Christensen ◽  
B D Owen

Abstract Amino acid analyses were performed on samples of blood, liver tissue, loin muscle, and ham muscle by ion exchange chromatography after deproteination of the samples with picric acid or sulfosalicylic acid (SSA). Resolution of threonine and serine from the ion exchange column was poor when SSA was used as the deproteinating agent. Twelve of sixteen amino acids were higher (P < 0.05) in serum deproteinated with picric acid as compared to concentrations determined after SSA deproteination. Amino acid values for ham muscle tended to be higher after deproteination with picric acid; however, with liver and loin muscle samples, the values were somewhat higher after SSA deproteination. In both serum and tissue analyses, coefficients of variation were lower for niGSt amino acids when picric acid was utilized as the deproteinating agent. The latter observation, in particular, suggests that picric acid is preferable to SSA as a deproteinating agent before amino acid analyses of biological fluids. Standardization of methods of deproteination is needed to allow meaningful comparisons of data.


1968 ◽  
Vol 106 (2) ◽  
pp. 531-541 ◽  
Author(s):  
P T Grant ◽  
K. B. M. Reid

1. Insulin has been isolated by gel filtration and ion-exchange chromatography from extracts of the discrete islet tissue of cod. The final preparation yielded a single band on electrophoresis at two pH values. The biological potency was 11·5 international units/mg. in mouse-convulsion and other assay procedures. 2. Glycine and methionine were shown to be the N-terminal amino acids of the A and B chains respectively. An estimate of the molecular weight together with amino acid analyses indicated that cod insulin, like the bovine hormone, consists of 51 amino acid residues. In contrast, the amino acid composition differs markedly from bovine insulin. 3. Oxidation of insulin with performic acid yielded the A and B peptide chains, which were separated by ion-exchange chromatography. Sequence studies on smaller peptides isolated from enzymic digests or from dilute acetic acid hydrolysates of the two chains have established the sequential order of 14 of the 21 amino acid residues of the A chain and 25 of the 30 amino acid residues of the B chain.


1973 ◽  
Vol 51 (6) ◽  
pp. 783-788 ◽  
Author(s):  
C. C. Yip ◽  
C. C. Liew

Slices of fetal bovine pancreas were used to study the initiation of proinsulin biosynthesis. The pancreatic slices were incubated with radioactive methionine, phenylalanine, or leucine, in a defined medium. The incorporation of amino acid into peptides in the tissue slices was measured for 2–3 h. Two types of radioactive peptides, "free" and "blocked," were identified by ion-exchange chromatography. Most of the radioactive "blocked" peptides labelled with [3H]phenylalanine and [35S]methionine were hydrolyzed by proteases, except for about 20% of those labelled with [35S]methionine, which also showed higher resistance to acid hydrolysis.Microsomes were isolated from the tissue slices after incubation and were extracted with acid alcohol. The radioactive proteins in the extract were reacted with a solid immunosorbant against insulin. Analysis of the immunoadsorbed radioactive peptides by Edman degradation showed the presence of both methionine and phenylalanine as the N-termini. It was concluded that methionine was an initiating amino acid in the biosynthesis of bovine proinsulin.


1980 ◽  
Vol 26 (12) ◽  
pp. 1450-1459 ◽  
Author(s):  
J. H. Tremaine ◽  
W. P. Ronald ◽  
E. M. Kelly

Southern bean mosaic virus (SBMV) protein was cleaved with cyanogen bromide and a highly basic peptide, CB-1, was isolated by ion exclusion and ion-exchange chromatography. Twelve peptides were separated from a tryptic digest of CB-1 by ion-exchange chromatography and the composition of these peptides was similar to that of peptides released from EDTA-swollen virus particles by limited tryptic digestion. The composition and N-termini of the tryptic peptides indicated CB-1 was from the N-terminus of SBMV protein and contained 48 amino acid residues. The CB-1 peptide moved rapidly to the cathode in polyacrylamide gel electrophoresis at pH 3.9 and contained nine arginine residues, three lysine residues, and no acidic amino acid residues. It was shown to interact with purified viral RNA, sodium dextran sulfate, and calf thymus DNA.Antiserum to sodium dodecyl sulfate (SDS)-dissociated virus gave a reaction of partial identity between the CB-1 peptide and the SDS-dissociated virus in SDS gel diffusion tests. The CB-1 peptide did not react with antiserum to SDS-dissociated, trypsin-treated virus. Gel diffusion tests conducted in saline agar gels between trypsin-treated virus and SBMV, with SBMV antiserum, did not show differences in their serological properties. Antiserum to the CB-1 peptide conjugated to tomato bushy stunt virus reacted with SBMV but SBMV antiserum did not react with CB-1 or the CB-1-tomato bushy stunt virus conjugate.


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