scholarly journals Synthesis of a Low-Molecular-Weight Form of Exopolysaccharide by Bradyrhizobium japonicum USDA 110

2001 ◽  
Vol 67 (2) ◽  
pp. 1011-1014 ◽  
Author(s):  
Heather A. Louch ◽  
Karen J. Miller
Keyword(s):  
Molecular Weight ◽  
Bradyrhizobium Japonicum ◽  
Compositional Analysis ◽  
Mass Spectrometry Analysis ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Spectrometry Analysis ◽  
Resonance Analysis ◽  
Dimeric Form ◽  
Molecular Weight Form

ABSTRACT A novel extracellular low-molecular-weight polysaccharide was detected as a contaminant within extracellular cyclic β-1,6-β-1,3-glucan preparations from Bradyrhizobium japonicum USDA 110 cultures. Compositional analysis, methylation analysis, and nuclear magnetic resonance analysis revealed that this low-molecular-weight polysaccharide was composed of the same pentasaccharide repeating unit previously described for the high-molecular-weight form of the exopolysaccharide (EPS) synthesized by B. japonicum strains. Mass spectrometry analysis indicated that the size of this low-molecular-weight form of EPS was consistent with a dimeric form of the pentasaccharide repeating unit.

Advances in structure elucidation of low molecular weight carbohydrates by liquid chromatography-multiple-stage mass spectrometry analysis

2020 ◽  
Vol 1612 ◽  
pp. 460664 ◽  
Author(s):  
A. Martín-Ortiz ◽  
C. Carrero-Carralero ◽  
O. Hernández-Hernández ◽  
R. Lebrón-Aguilar ◽  
F.J. Moreno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Liquid Chromatography ◽  
Structure Elucidation ◽  
Mass Spectrometry Analysis ◽  
Low Molecular Weight ◽  
Spectrometry Analysis

scholarly journals Alcoholytic Cleavage of Polyhydroxyalkanoate Chains by Class IV Synthases Induced by Endogenous and Exogenous Ethanol

2013 ◽  
Vol 80 (4) ◽  
pp. 1421-1429 ◽  
Author(s):  
Manami Hyakutake ◽  
Satoshi Tomizawa ◽  
Kouhei Mizuno ◽  
Hideki Abe ◽  
Takeharu Tsuge
Keyword(s):  
Molecular Weight ◽  
Pha Synthase ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Content Type ◽  
Resonance Analysis ◽  
Inherent Feature ◽  
Class Iv

ABSTRACTPolyhydroxyalkanoate (PHA)-producingBacillusstrains express class IV PHA synthase, which is composed of the subunits PhaR and PhaC. RecombinantEscherichia coliexpressing PHA synthase fromBacillus cereusstrain YB-4 (PhaRCYB-4) showed an unusual reduction of the molecular weight of PHA produced during the stationary phase of growth. Nuclear magnetic resonance analysis of the low-molecular-weight PHA revealed that its carboxy end structure was capped by ethanol, suggesting that the molecular weight reduction was the result of alcoholytic cleavage of PHA chains by PhaRCYB-4induced by endogenous ethanol. This scission reaction was also induced by exogenous ethanol in bothin vivoandin vitroassays. In addition, PhaRCYB-4was observed to have alcoholysis activity for PHA chains synthesized by other synthases. The PHA synthase fromBacillus megaterium(PhaRCBm) from another subgroup of class IV synthases was also assayed and was shown to have weak alcoholysis activity for PHA chains. These results suggest that class IV synthases may commonly share alcoholysis activity as an inherent feature.

Low-molecular-weight styrene–butadiene copolymers (L-SSBR) as processing aids used for silica-filled rubber: Synthesis, functionalization and application

2018 ◽  
Vol 51 (3) ◽  
pp. 244-261
Author(s):  
Barbara Robak ◽  
Jarosław Rogoża ◽  
Mieczysław Łapkowski
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Low Molecular Weight ◽  
Nuclear Magnetic Resonance Analysis ◽  
Resonance Analysis ◽  
Filled Rubber ◽  
Cure Characteristic ◽  
Styrene Butadiene

Three different types of low-molecular-weight solution styrene-butadiene rubbers (L-SSBRs) were synthesized by anionic polymerization. Two of them were end-capped with methoxy (M-L-SSBR) and ethoxy (E-L-SSBR) functional groups, respectively, while the other was terminated with alcohol (L-SSBR). The content of functional groups was estimated on the basis of gel permeation chromatography and proton nuclear magnetic resonance analysis. The influence of L-SSBR on the properties of silica-filled SSBR as an alternative for the plasticizing oil was investigated in tyre tread formulation. L-SSBRs of high vinyl content were used in place of part of oil for preparation of compound K1 enriched with linear (L-SSBR) and compound K2 and K3 enriched with two star-like liquid rubbers modified, respectively, with methoxy (M-L-SSBR) and ethoxy (E-L-SSBR) functional groups. Although particular attention was paid to the effect of polar groups on the silica dispersions, cure characteristic, compound viscosity and mechanical properties were also analyzed. Rubber with only treated distillate aromatic extract was used (K5) as the reference.

scholarly journals The Purification of Low Molecular Weight Form of Polypeptide Elongation Factor 1 from Pig Liver

1974 ◽  
Vol 249 (15) ◽  
pp. 5008-5010
Author(s):  
Kentaro Iwasaki ◽  
Shigekazu Nagata ◽  
Kiyohisa Mizumoto ◽  
Yoshito Kaziro
Keyword(s):  
Molecular Weight ◽  
Elongation Factor ◽  
Low Molecular Weight ◽  
Pig Liver ◽  
Elongation Factor 1 ◽  
Molecular Weight Form
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