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The Journal of Biological Chemistry Mar 1954
Topics: Alcohol Dehydrogenase; Biophysical Phenomena; Coenzymes; Molecular Weight; Oxidation-Reduction; Oxidoreductases
PubMed: 13152098
DOI: No ID Found -
Environmental Science & Technology Jan 2018We reassessed the molecular weight of dissolved organic matter (DOM) determined by high pressure size exclusion chromatography (HPSEC) using measurements made with...
High Pressure Size Exclusion Chromatography (HPSEC) Determination of Dissolved Organic Matter Molecular Weight Revisited: Accounting for Changes in Stationary Phases, Analytical Standards, and Isolation Methods.
We reassessed the molecular weight of dissolved organic matter (DOM) determined by high pressure size exclusion chromatography (HPSEC) using measurements made with different columns and various generations of polystyrenesulfonate (PSS) molecular weight standards. Molecular weight measurements made with a newer generation HPSEC column and PSS standards from more recent lots are roughly 200 to 400 Da lower than initial measurements made in the early 1990s. These updated numbers match DOM molecular weights measured by colligative methods and fall within a range of values calculated from hydroxyl radical kinetics. These changes suggest improved accuracy of HPSEC molecular weight measurements that we attribute to improved accuracy of PSS standards and changes in the column packing. We also isolated DOM from wetlands in the Prairie Pothole Region (PPR) using XAD-8, a cation exchange resin, and PPL, a styrene-divinylbenzene media, and observed little difference in molecular weight and specific UV absorbance at 280 nm (SUVA) between the two solid phase extraction resins, suggesting they capture similar DOM moieties. PPR DOM also showed lower SUVA at similar weights compared to DOM isolates from a global range of environments, which we attribute to oxidized sulfur in PPR DOM that would increase molecular weight without affecting SUVA.
Topics: Chromatography, Gel; Hydroxyl Radical; Molecular Weight; Reference Standards; Solid Phase Extraction
PubMed: 29185717
DOI: 10.1021/acs.est.7b04401 -
Biochemistry Feb 1966
Topics: Chemical Phenomena; Chemistry, Physical; Molecular Weight; Muscle Proteins; Ultracentrifugation
PubMed: 5942951
DOI: 10.1021/bi00866a017 -
Archives of Biochemistry Sep 1946
Topics: Humans; Molecular Weight; Solubility
PubMed: 20998039
DOI: No ID Found -
Journal of Clinical Pathology Sep 1975
Topics: Electrophoresis, Polyacrylamide Gel; Molecular Weight
PubMed: 1165317
DOI: 10.1136/jcp.28.9.758-b -
Zhongguo Zhong Yao Za Zhi = Zhongguo... Mar 2024Polysaccharides from medicinal plant resources are a kind of polymers extracted from medicinal plants. They are complex long chains formed by different monosaccharides...
Polysaccharides from medicinal plant resources are a kind of polymers extracted from medicinal plants. They are complex long chains formed by different monosaccharides connected via glucosidic bonds. These polysaccharides usually have straight chain and branched chain structures, and their relative molecular weight changes greatly. Modern studies have shown that the biological activi-ty of polysaccharides from medicinal plant resources is closely related to their relative molecular weight. This paper first reviewed the preparation and detection methods of polysaccharides from medicinal plant resources with different relative molecular weights. Then, the paper summarized and analyzed the general experience of the correlation between efficacy and relative molecular weight of polysaccharides from medicinal plant resources with different molecular weights. It was considered that polysaccharides with large relative molecular weights(>100 kDa) play a leading role in immune regulation. Polysaccharides with medium relative molecular weights(10-100 kDa) play a leading role in immune regulation and the protection of the liver. Polysaccharides with small relative molecular weights(<10 kDa) play a leading role in anti-oxidation, regulation of intestinal flora, regulation of blood glucose and lipids, anti-fatigue, and the protection of nerves. Therefore, precise development of polysaccharides from medicinal plant resources based on relative molecular weight is expected to improve their biological activity and application value.
Topics: Plants, Medicinal; Molecular Weight; Polysaccharides; Monosaccharides
PubMed: 38621965
DOI: 10.19540/j.cnki.cjcmm.20231221.601 -
Nature Jan 1956
Topics: Chlorophyll; Eukaryota; Molecular Weight
PubMed: 13288616
DOI: 10.1038/177136a0 -
Nature Mar 1946
Topics: Molecular Weight; Proteins
PubMed: 21024261
DOI: 10.1038/157408a0 -
Archives of Biochemistry and Biophysics Dec 1958
Topics: Dextrans; Humans; Molecular Weight
PubMed: 13618012
DOI: 10.1016/0003-9861(58)90354-0 -
Immunology Jan 1962Passive cutaneous anaphylaxis in the guinea pig has been studied with rabbit antibody to a series of antigens of differing molecular weight. The results indicated that...
Passive cutaneous anaphylaxis in the guinea pig has been studied with rabbit antibody to a series of antigens of differing molecular weight. The results indicated that at a given antibody level the weight of antigen needed to elicit a reaction increases with its molecular weight. Previous observations have been confirmed that the amount of antigen needed to elicit a reaction at a high level of antibody is less than that required at a lower level. The results suggest that extremely small amounts of small molecular weight antigens might be sufficient to produce anaphylactic symptoms in highly sensitive individuals.
Topics: Antigens; Hypersensitivity; Immune System Diseases; Molecular Weight; Passive Cutaneous Anaphylaxis
PubMed: 14464304
DOI: No ID Found