Microbial pectinolytic enzymes: A review

Extracellular polymeric substances (EPS) produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids and humic substances. EPS make up the intercellular space of microbial aggregates and form the structure and architecture of the biofilm matrix. The key functions of EPS comprise the mediation of the initial attachment of cells to different substrata and protection against environmental stress and dehydration. The aim of this review is to present a summary of the current status of the research into the role of EPS in bacterial attachment followed by biofilm formation. The latter has a profound impact on an array of biomedical, biotechnology and industrial fields including pharmaceutical and surgical applications, food engineering, bioremediation and biohydrometallurgy. The diverse structural variations of EPS produced by bacteria of different taxonomic lineages, together with examples of biotechnological applications, are discussed. Finally, a range of novel techniques that can be used in studies involving biofilm-specific polysaccharides is discussed.

https://www.mdpi.com/1420-3049/14/7/2535/pdf

Bacterial extracellular polysaccharides involved in biofilm formation.

https://www.cell.com/trends/neurosciences/pdf/S0166-2236(08)00163-X.pdf

Neuronal calcium mishandling and the pathogenesis of Alzheimer's disease.

Phosphatidylserine (PS) is the most abundant negatively charged phospholipid in eukaryotic membranes. PS directs the binding of proteins that bear C2 or gamma-carboxyglutamic domains and contributes to the electrostatic association of polycationic ligands with cellular membranes. Rather than being evenly distributed, PS is found preferentially in the inner leaflet of the plasma membrane and in endocytic membranes. The loss of PS asymmetry is an early indicator of apoptosis and serves as a signal to initiate blood clotting. This review discusses the determinants and functional implications of the subcellular distribution and membrane topology of PS.

The distribution and function of phosphatidylserine in cellular membranes.

Autoimmunity and the Clearance of Dead Cells

Biocatalytic reduction catalysed by alcohol dehydrogenases is a valuable tool for asymmetric synthesis of chiral alcohols. This study reports the broad substrate specificity of NADH dependent ( S ) - specific alcohol dehydrogenase (S-ADH) purified from Candida parapsilosis ATCC 7330. The substrates for this enzyme include aliphatic and aromatic ketones, cyclic and diketones, aldehydes, ketoesters, primary and secondary alcohols. The kinetic studies of different substrates indicate that ketones and secondary alcohols are the most preferred substrates of S-ADH with highest catalytic efficiencies reported for reduction of acetone (4153 s −1 mM −1 ) and oxidation of 2-propanol (1358 s −1 mM −1 ). The double reciprocal plots obtained for varied concentrations of acetophenone (0.2–16 mM) at a fixed concentration of NADH (0.05, 0.1 and 0.2 mM) and with varied concentrations of NADH (0.01–0.2 mM) at a fixed concentration of acetophenone (1, 4, 8 and 16 mM) showed intersecting lines indicating sequential kinetic mechanism. S-ADH follows Prelog's stereopreference in reducing prochiral carbonyl substrates to yield ( S )-alcohols with >99% enantiomeric excess using a simple coupled substrate approach for cofactor recycling. • S-ADH accepts ketones, aldehydes, primary and secondary alcohols as the substrates. • Ketones and secondary alcohols are the most preferred substrates of S-ADH. • It shows sequential kinetic mechanism. • It follows Prelog's stereopreference in reducing prochiral carbonyl substrates. 

Substrate selectivity and kinetic studies of (S)-specific alcohol dehydrogenase purified from Candida parapsilosis ATCC 7330

In this study, the SCRM-1 gene from Caenorhabditis elegans was cloned and overexpressed in E. coli to study the biochemical properties of scramblase. This is the first report showing that this scramblase from C. elegans possesses a Ca2+-dependent and head group-independent scramblase activity. The SCRM-1 of C.elegans possesses functional domains including a single EF-hand-like Ca2+ binding domain, as human scramblases do. A point mutation in the EF-hand-like Ca2+ binding motif results in loss of scramblase activity. Other biochemical assays like carbocyanine staining, Tb3+ luminescence, Tryptophan fluorescence, and CD spectroscopy strongly proved the role of the EF-hand motif for functional activity. The increase in protein size in solution upon incubating with Ca2+ shows ligand-dependent oligomerization and conformational changes.

Molecular cloning and biochemical characterization of the phospholipid scramblase SCRM-1 from Caenorhabditis elegans

/pdf/mathematical-modeling-of-macroscale-phenomena-oxygen-31bw61tj6t.pdf

Mathematical Modeling of Macroscale Phenomena: Oxygen Transfer for Solid-state Fermentation in Static Tray Bioreactor

pH and temperature are the most predominant parameters affecting protein macromolecular properties like activity and stability. Optimisation of these parameters is crucial for their industrial appl...

Optimisation of physical parameters pH and temperature for maximised activity and stability of Vibrio cholerae L-asparaginase by statistical experimental design

Sathyanarayana N. Gummadi

Papers

Substrate selectivity and kinetic studies of (S)-specific alcohol dehydrogenase purified from Candida parapsilosis ATCC 7330

Molecular cloning and biochemical characterization of the phospholipid scramblase SCRM-1 from Caenorhabditis elegans

Mathematical Modeling of Macroscale Phenomena: Oxygen Transfer for Solid-state Fermentation in Static Tray Bioreactor

Optimisation of physical parameters pH and temperature for maximised activity and stability of Vibrio cholerae L-asparaginase by statistical experimental design

Snail represses the expression of human phospholipid scramblase 4 gene.