scholarly journals The W and L allelic forms of phenylalanine hydroxylase in the rat differ by a threonine to isoleucine substitution

1986 ◽  
Vol 236 (3) ◽  
pp. 679-683 ◽  
Author(s):  
J F B Mercer ◽  
W McAdam ◽  
G W Chambers ◽  
I D Walker
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Sodium Dodecyl Sulphate ◽  
High Performance ◽  
Phenylalanine Hydroxylase ◽  
Sodium Dodecyl ◽  
Amino Acid Position ◽  
Peptide Sequencing ◽  
Nucleotide Change ◽  
Allelic Substitution

High performance liquid chromatography maps of tryptic and chymotryptic peptides from the W and L forms of rat phenylalanine hydroxylase differed by one peptide. Sequencing of the variant tryptic peptides showed a substitution of threonine in the W form by isoleucine in the L form and this same difference was confirmed in the chymotryptic peptides. This allelic substitution would result from a nucleotide change of ACA to ATA at amino acid position 371 of the full phenylalanine hydroxylase sequence. Altered sodium dodecyl sulphate binding is postulated to explain the change in mobility of the proteins observed on sodium dodecyl sulphate/polyacrylamide gels.

SELECTION OF COLUMN AND OPERATING CONDITIONS FOR REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF PROTEINS IN CANADIAN WHEAT

1985 ◽  
Vol 65 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J. E. KRUGER ◽  
B. A. MARCHYLO
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Storage Proteins ◽  
Sodium Dodecyl ◽  
Reversed Phase ◽  
Operating Conditions ◽  
Protein Patterns ◽  
Optimal Separation ◽  
Rp Hplc

Chromatographic conditions were optimized and three commercially available columns were evaluated for separation of alcohol-soluble storage proteins of Neepawa wheat using reversed-phase high-performance liquid chromatography (RP-HPLC). Optimal separation was achieved using an extracting solution of 50% 1-propanol, 1% acetic acid, and 4% dithiothreitol and an HPLC elution time of 105 min at a flow rate of 1.0 mL/min. HPLC columns evaluated (SynChropak RP-P, Ultrapore RPSC and Aquapore RP-300) varied in selectivity and resolution. The column providing the greatest versatility was Aquapore RP-300 available in cartridge form. Sodium dodecyl sulfate gradient-gel electrophoresis analysis of protein peaks resolved by RP-HPLC indicated that many of the eluted peaks contained more than one protein species. Chromatographic protein patterns obtained for Neepawa wheat grown at different locations and in different years were qualitatively the same.Key words: Protein, high-performance liquid chromatography, wheat

scholarly journals Estimation of Some Useful Drugs in Water, Urine, and Medical Formulations Following Conventional and Modified Dispersive Microextraction Coupled with HPLC-UV

2021 ◽  
pp. 11-33
Author(s):  
Mitali Sarkar ◽  
Shanku Denrah
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Extraction Efficiency ◽  
Sodium Dodecyl ◽  
Two Phase ◽  
Preconcentration Factor ◽  
Dispersive Microextraction ◽  
Dispersive Liquid Liquid Microextraction ◽  
Thermodynamic Feasibility

Dispersive Liquid-Liquid Microextraction (DLLME) coupled with high-performance liquid chromatography-ultraviolet spectroscopy was developed, as a fast and precise operation, for extractive recovery and estimation of two pharmaceuticals viz. moxifloxacin and galantamine, from water, urine, and medical formulations. The process was investigated for Extraction (ES) and Dispersive Solvent (DS) as well as pH, temperature, and salt concentration. Extraction was found effective using methanol (CH3OH), as the DS, employing 1,1,2,2-tetrachloroethane (C2H2Cl4) and chloroform (CHCl3), as the ES, for moxifloxacin and galantamine respectively. The optimum pH was found to be 6.9 for moxifloxacin and 10.2 for galantamine. Temperature and salt were found to have some influence on the extraction efficiency of moxifloxacin but insignificant for galantamine. An improvement of the operation in terms of the Extraction efficiency (ER %), Preconcentration Factor (PF), thermodynamic feasibility, and greenness were achieved during surfactant aided DLLME (SDS-DLLME), where anionic surfactant (Sodium Dodecyl Sulphate (SDS)) was employed and no DS was required. Interestingly, the volume requirement for ES was found less, compared to that in the conventional DLLME, without compromising the performance. Moreover, quantitative recovery of both the drugs was achieved using a single ES. Thus, mutual separation and simultaneous determination of moxifloxacin and galantamine may be designed. A two-phase separation with concomitant enrichment of the solute in the sediment phase occurred. The drugs in the sediment phase, on subsequent dilution with methanol, were determined using the High Performance Liquid Chromatography-Ultraviolet (HPLC-UV) system. The negative free energy changes for the operation indicated that the process was thermodynamically feasible. The process was found to be effective for the spiked recovery of the studied drugs from real samples viz, water, human urine, and commercial medical formulations.

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