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 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 The Determination of N-terminal Amino Acids during the Conversion of Fibrinogen to Fibrin.

1957 ◽  
Vol 11 ◽  
pp. 194-195 ◽  
Author(s):  
Birger Blombäck ◽  
Ikuo Yamashina ◽  
S. Ross ◽  
J. Schliack ◽  
L. Reio
Keyword(s):  
Amino Acids ◽  
Terminal Amino

scholarly journals Determination of Caffeine and Taurine Contents in Energy Drinks by HPLC-UV

2016 ◽  
Vol 9 ◽  
pp. 66-73 ◽  
Author(s):  
Krishna Prasad Rai ◽  
Hasta Bahadur Rai ◽  
Santosh Dahal ◽  
Saroj Chaudhary ◽  
Suraj Shrestha
Keyword(s):  
Amino Acids ◽  
Pilot Study ◽  
Quantitative Determination ◽  
Physiological Responses ◽  
Alcoholic Beverage ◽  
Energy Drinks ◽  
Energy Drink ◽  
Young Generation ◽  
Caffeine Content

Energy drinks are non-alcoholic beverage intended to enhance the psycho-physiological responses in human, which is especially popular among young generation in Nepal. It is normally high caffeinated drink added with other ingredients such as carbohydrates, amino acids, B-group of vitamins etc. In this study, 10 brands of energy drink available in Nepalese markets were taken then analyzed for quantitative determination of Caffeine and Taurine by HPLC-UV method. From the result obtained, pH and TSS values of energy drinks were found in the range of 2.96-3.81 and 6.64-18.21 respectively. Likewise, the Caffeine and Taurine content in same samples were found in the range of not detected (ND) to 35.78 mg/100 ml and ND to 387.5 mg/100 ml respectively. Only the 6 samples out of 10 were confi rmed caffeine content as per claimed in label, while only 3 samples were confi rmed for Taurine content as per label claimed. Based on this pilot study, the majority of samples did not meet the label claims in term of Caffeine and Taurine, which apparently indicated the misbranding of such drinks. Since, there is no any regulation for such energy drinks in Nepal, it seems to be a great challenge for regulation of their safety and misbranding.

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