scholarly journals Qualitative determination of N-terminal amino acids of peptides and proteins with cobalt(III) chelates

1973 ◽  
Vol 135 (3) ◽  
pp. 507-511 ◽  
Author(s):  
Keith W. Bentley ◽  
Ernest H. Creaser
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cobalt Complex ◽  
Peptide Bond ◽  
Small Peptides ◽  
Amino Acid Determination ◽  
Terminal Amino ◽  
Qualitative Determination ◽  
High Voltage Electrophoresis

1. A method of N-terminal peptide-bond hydrolysis with the cis-β-hydroxyaquo(triethylenetetramine)cobalt(III) ion, i.e. β-[Co(trien)(OH)(OH2)]2+, is reported. The method has been demonstrated with 22 small peptides and ten proteins. 2. The procedure is rapid (an N-terminal amino acid determination can be made easily in one day), it involves no acid hydrolysis step and thus no destruction of labile amino acids, and it involves the use of easily prepared inexpensive reagents. 3. The released N-terminal amino acids can be identified as their cobalt(III) derivatives, or directly as the amino acid or as their dansylated derivatives. 4. The method is to treat 1 μmol of peptide or protein with β-[Co(trien)(OH)(OH2)]2+ reagent at pH8.0, 45°C for 3h. Addition of 0.5m-phosphate buffer, pH10.5 at 45°C for 10min cleaves the N-terminal bidentate amino acid–cobalt complex, which can be identified directly. For greater sensitivity with 10nmol of peptide) the free amino acid is prepared from the complex by treatment (with NaCN (0.1m, 40°C, 30min), or H2S or NaBH4 (25°C, 5min), dried, dansylated and the dansyl-amino acid identified by high-voltage electrophoresis. The method is unaffected by the presence of 4–8m-urea, but will not cleave blocked N-terminal acids.

scholarly journals Quantitative determination of N-terminal amino acids of peptides and proteins with cobalt(III) chelates

1976 ◽  
Vol 153 (1) ◽  
pp. 137-138 ◽  
Author(s):  
K W Bentley
Keyword(s):  
Amino Acids ◽  
Quantitative Determination ◽  
Peptide Bond ◽  
Small Peptides ◽  
Acidic Hydrolysis ◽  
Terminal Amino ◽  
A Chain ◽  
Glucagon And Insulin

Quantitative N-terminal peptide-bond hydrolysis with the cis-beta-hydroxyaquo(triethylenetetramine) cobal (III) ion, i.e. β-[Co(trien)(OH)(OH2)]2+, is reported. The method has been demonstrated with 20 small peptides, a hexapeptide, bradykinin, insulin A chain (oxidized), glucagon and insulin. The procedure involves no acidic hydrolysis step and thus no destruction of labile amino acids.

scholarly journals Determination of free amino acids in plants by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)

2015 ◽  
Vol 7 (18) ◽  
pp. 7574-7581 ◽  
Author(s):  
Magdalena M. Dziągwa-Becker ◽  
Jose M. Marin Ramos ◽  
Jakub K. Topolski ◽  
Wiesław A. Oleszek
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Liquid Chromatography ◽  
Amino Acid ◽  
Tandem Mass Spectrometry ◽  
Free Amino ◽  
Tandem Mass ◽  
Amino Acid Determination ◽  
Acid Determination

Free amino acid determination in plants by LC-MS/MS.

PURIFICATION AND PARTIAL CHEMICAL CHARACTERIZATION OF SHEEP NEUROPHYSIN

1973 ◽  
Vol 74 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Michel Chrétien ◽  
Claude Gilardeau
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chemical Characterization ◽  
Terminal Amino Acid ◽  
Amino Acid Determination ◽  
Pituitary Glands ◽  
Terminal Amino ◽  
Partial Chemical ◽  
Acid Determination

ABSTRACT A protein isolated from ovine pituitary glands has been purified, and its homogeneity assessed by NH2- and COOH-terminal amino acid determination, ultracentrifugation studies, and polyacrylamide gel electrophoresis after carboxymethylation. Its chemical and immunochemical properties are closely similar to those of beef and pork neurophysins, less similar to those of human neurophysins. It contains no tryptophan (like other neurophysins) or histidine (like all except bovine neurophysin-I and human neurophysins). It has alanine at the NH2-terminus and valine at the COOH-terminus. Its amino acid composition is similar to, but not identical with those of porcine and bovine neurophysins.

scholarly journals Determination of amino acids in human biological fluids by high-performance liquid chromatography: critical review

Amino Acids ◽  
2021 ◽  
Author(s):  
Grażyna Gałęzowska ◽  
Joanna Ratajczyk ◽  
Lidia Wolska
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
High Performance ◽  
Hplc Analysis ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
Analytical Techniques ◽  
Epidemiological Studies ◽  
Preparation Conditions

AbstractThe quantitation and qualification of amino acids are most commonly used in clinical and epidemiological studies, and provide an excellent way of monitoring compounds in human fluids which have not been monitored previously, to prevent some diseases. Because of this, it is not surprising that scientific interest in evaluating these compounds has resurfaced in recent years and has precipitated the development of a multitude of new analytical techniques. This review considers recent developments in HPLC analytics on the basis of publications from the last few years. It helps to update and systematize knowledge in this area. Particular attention is paid to the progress of analytical methods, pointing out the advantages and drawbacks of the various techniques used for the preparation, separation and determination of amino acids. Depending on the type of sample, the preparation conditions for HPLC analysis change. For this reason, the review has focused on three types of samples, namely urine, blood and cerebrospinal fluid. Despite time-consuming sample preparation before HPLC analysis, an additional derivatization technique should be used, depending on the detection technique used. There are proposals for columns that are specially modified for amino acid separation without derivatization, but the limit of detection of the substance is less beneficial. In view of the fact that amino acid analyses have been performed for years and new solutions may generate increased costs, it may turn out that older proposals are much more advantageous.

scholarly journals Roles of the C-Terminal Amino Acids of Non-Hexameric Helicases: Insights from Escherichia coli UvrD

2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Single Molecule ◽  
Underlying Mechanism ◽  
Amino Acid Sequences ◽  
E Coli ◽  
X Ray Crystallography ◽  
Terminal Amino

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.

scholarly journals Determination of Methylated Basic Amino Acids with the Amino Acid Analyzer

1973 ◽  
Vol 248 (7) ◽  
pp. 2387-2391 ◽  
Author(s):  
Gladys E. Deibler ◽  
Russell E. Martenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acids ◽  
Amino Acid Analyzer

SOME ASPECTS OF THE STRUCTURE OF HEMOGLOBIN

1964 ◽  
Vol 42 (6) ◽  
pp. 755-762 ◽  
Author(s):  
David B. Smith
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Partial Amino Acid Sequence ◽  
Heme Pocket ◽  
Terminal Amino ◽  
Polypeptide Chains ◽  
Kinetics Of ◽  
Β Chain

An outline of present ideas concerning the arrangement, folding, and chemistry of the polypeptide chains of hemoglobin is given with some references to present know ledge of myoglobin.New material includes a partial amino acid sequence of the β-chain of horse hemoglobin, details concerning the amino acids lining the heme pocket of horse hemoglobin, and the effects of carboxypeptidases A and B on horse oxy- and horse deoxy-hemoglobin. The kinetics of the latter reactions are not simple. The C-terminal amino acids are released more rapidly from the oxygenated form.

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