Size Exclusion Chromatography with Multi Detection in Combination with Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry as a Tool for Unraveling the Mechanism of the Enzymatic Polymerization of Polysaccharides
Determination of the size distributions of natural polysaccharides is a challenging task. More advantageous for characterization are well-defined synthetic (hyper)-branched polymers. In this study we concentrated on synthetic amylopectin analogues in order to obtain and compare all available data for different distributions and size dependence of molecular weights. Two groups of well-defined synthetic branched polysaccharides were synthesized via an in vitro enzyme-catalyzed reaction using the enzyme phosphorylase b from rabbit muscle and Deinococcus geothermalis glycogen branching enzyme. Synthetic polymers had a tunable degree of branching (2%–13% determined via 1H NMR) and a tunable degree of polymerization (30–350 determined indirectly via UV spectrometry). The systems used for separation and characterization of branched polysaccharides were SEC-DMSO/LiBr and multi detection (refractive index detector, viscosity detector, and multi angle light scattering detector) and SEC-water/0.02% NaN3; and SEC-50 ...
Jelena Ciric; Jorrit Oostland; Jan Willem de Vries; Albert J. J. Woortman; Katja Loos
We recently generalized the formerly alignment-dependent multivariate image analysis applied to quantitative structure–activity relationships (MIA-QSAR) method through the application of the discrete Fourier transform (DFT), allowing for its application to noncongruent and structurally dive ... more
Poly-ADP-ribosylation (PARylation) is a protein posttranslational modification (PTM) that is critically involved in many biological processes that are linked to cell stress responses. It is catalyzed by a class of enzymes known as poly-ADP-ribose polymerases (PARPs). In particular, PARP1 is ... more
This review focuses on the type A cytochrome c oxidases (CcO), which are found in all mitochondria and also in several aerobic bacteria. CcO catalyzes the respiratory reduction of dioxygen (O2) to water by an intriguing mechanism, the details of which are fairly well understood today as a r ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more