scholarly journals Determination of ionization constants by paper electrophoresis

1981 ◽  
Vol 195 (2) ◽  
pp. 419-426 ◽  
Author(s):  
M E Tate
Keyword(s):  
Molecular Weight ◽  
Cyclic Amp ◽  
Paper Electrophoresis ◽  
Ionization Constants ◽  
Low Molecular Weight ◽  
Electrophoretic Data ◽  
Oxalate Ions

Dimensionless apparent ionization constants of charged low-molecular-weight species may be obtained from paper-electrophoretic data at 20-25 degrees C with buffers (I0.1-0.5) of measured pH (1.5-12.5) containing oxalate ions. Relative mobilities rather than absolute mobilities were measured by using glycerol and m-nitrobenzenesulphonate respectively as standards of zero and unit mobility. Application of the procedure to ionizations of adenine, adenosine, 2′-deoxyadenosine, 3′-deoxyadenosine, 3′:5′-cyclic AMP, ADP, ADP-glucose-agrocin 84 and ATP is described.

scholarly journals Simultaneous Determination of Human Serum Albumin and Low-Molecular-Weight Thiols after Derivatization with Monobromobimane

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3321
Author(s):  
Katarzyna Kurpet ◽  
Rafał Głowacki ◽  
Grażyna Chwatko
Keyword(s):  
Molecular Weight ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Simultaneous Determination ◽  
Reversed Phase ◽  
Fluorescence Labeling ◽  
Detector Response ◽  
Low Molecular Weight

Biothiols are extremely powerful antioxidants that protect cells against the effects of oxidative stress. They are also considered relevant disease biomarkers, specifically risk factors for cardiovascular disease. In this paper, a new procedure for the simultaneous determination of human serum albumin and low-molecular-weight thiols in plasma is described. The method is based on the pre-column derivatization of analytes with a thiol-specific fluorescence labeling reagent, monobromobimane, followed by separation and quantification through reversed-phase high-performance liquid chromatography with fluorescence detection (excitation, 378 nm; emission, 492 nm). Prior to the derivatization step, the oxidized thiols are converted to their reduced forms by reductive cleavage with sodium borohydride. Linearity in the detector response for total thiols was observed in the following ranges: 1.76–30.0 mg mL−1 for human serum albumin, 0.29–5.0 nmol mL−1 for α-lipoic acid, 1.16–35 nmol mL−1 for glutathione, 9.83–450.0 nmol mL−1 for cysteine, 0.55–40.0 nmol mL−1 for homocysteine, 0.34–50.0 nmol mL−1 for N-acetyl-L-cysteine, and 1.45–45.0 nmol mL−1 for cysteinylglycine. Recovery values of 85.16–119.48% were recorded for all the analytes. The developed method is sensitive, repeatable, and linear within the expected ranges of total thiols. The devised procedure can be applied to plasma samples to monitor biochemical processes in various pathophysiological states.

scholarly journals Proteomic Determination of Low-Molecular-Weight Glutenin Subunit Composition in Aroona Near-Isogenic Lines and Standard Wheat Cultivars

2021 ◽  
Vol 22 (14) ◽  
pp. 7709
Author(s):  
Kyoungwon Cho ◽  
You-Ran Jang ◽  
Sun-Hyung Lim ◽  
Susan B. Altenbach ◽  
Yong Q. Gu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Allelic Variation ◽  
Reversed Phase ◽  
Glutenin Subunit ◽  
Low Molecular Weight ◽  
Near Isogenic Lines ◽  
Wheat Cultivars ◽  
Reliable Determination ◽  
Isogenic Lines

The low-molecular weight glutenin subunit (LMW-GS) composition of wheat (Triticum aestivum) flour has important effects on end-use quality. However, assessing the contributions of each LMW-GS to flour quality remains challenging because of the complex LMW-GS composition and allelic variation among wheat cultivars. Therefore, accurate and reliable determination of LMW-GS alleles in germplasm remains an important challenge for wheat breeding. In this study, we used an optimized reversed-phase HPLC method and proteomics approach comprising 2-D gels coupled with liquid chromatography–tandem mass spectrometry (MS/MS) to discriminate individual LMW-GSs corresponding to alleles encoded by the Glu-A3, Glu-B3, and Glu-D3 loci in the ‘Aroona’ cultivar and 12 ‘Aroona’ near-isogenic lines (ARILs), which contain unique LMW-GS alleles in the same genetic background. The LMW-GS separation patterns for ‘Aroona’ and ARILs on chromatograms and 2-D gels were consistent with those from a set of 10 standard wheat cultivars for Glu-3. Furthermore, 12 previously uncharacterized spots in ‘Aroona’ and ARILs were excised from 2-D gels, digested with chymotrypsin, and subjected to MS/MS. We identified their gene haplotypes and created a 2-D gel map of LMW-GS alleles in the germplasm for breeding and screening for desirable LMW-GS alleles for wheat quality improvement.

scholarly journals Cyclic AMP and Low Molecular Weight Effector(s) Present in Yeast Extract Are Involved in Pectin Lyase Production by Penicillium griseoroseum Cultured on Sucrose

1999 ◽  
Vol 76 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Maria Cristina Baracat-Pereira ◽  
Jorge Luiz Cavalcante Coelho ◽  
Rosana Cristina Minussi ◽  
Virgínia Maria Chaves-Alves ◽  
Rogelio Lopes Brandio ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cyclic Amp ◽  
Yeast Extract ◽  
Pectin Lyase ◽  
Low Molecular Weight ◽  
Penicillium Griseoroseum

METHODS FOR REDUCING THE DETECTION LIMIT OF IMMUNOCHROMATOGRAPHIC TEST SYSTEMS FOR ANTIBIOTIC CONTROL IN HONEY

2021 ◽  
Vol 1 (19) ◽  
pp. 219-220
Author(s):  
L. Barshevskaya ◽  
D. Sotnikov ◽  
A. Zherdev ◽  
B. Dzantiev
Keyword(s):  
Molecular Weight ◽  
Detection Limit ◽  
Low Molecular Weight ◽  
Immunochromatographic Test ◽  
Test Systems ◽  
Antibiotic Control

Methods for increasing the sensitivity of immunochromatographic test systems for the determination of low molecular weight analytes are proposed. The developed analysis schemes were tested in the determination of sulfonylamide and chloramphenicol in honey.

Peptidylation for the determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

The Analyst ◽  
2016 ◽  
Vol 141 (11) ◽  
pp. 3259-3265 ◽  
Author(s):  
Feng Tang ◽  
Si-Ying Cen ◽  
Huan He ◽  
Yi Liu ◽  
Bi-Feng Yuan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Laser Desorption ◽  
Low Molecular Weight ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Low Molecular Weight Compounds ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

A universal peptide-based derivatization (peptidylation) strategy for the sensitive detection of low-molecular-weight compounds by MALDI-TOF-MS was developed.

Sign in / Sign up

Export Citation Format

Share Document