Search results for "Cero"

Model-based biotechnological potential analysis of Kluyveromyces marxianus central metabolism

2016

Abstract The non-conventional yeast Kluyveromyces marxianus is an emerging industrial producer for many biotechnological processes. Here, we show the application of a biomass-linked stoichiometric model of central metabolism that is experimentally validated, and mass and charge balanced for assessing the carbon conversion efficiency of wild type and modified K. marxianus. Pairs of substrates (lactose, glucose, inulin, xylose) and products (ethanol, acetate, lactate, glycerol, ethyl acetate, succinate, glutamate, phenylethanol and phenylalanine) are examined by various modelling and optimisation methods. Our model reveals the organism’s potential for industrial application and metabolic engi…

The GlpF residue Trp219 is part of an amino-acid cluster crucial for aquaglyceroporin oligomerization and function

2018

The vestibule loop regions of aquaglyceroporins are involved in accumulation of glycerol inside the channel pore. Even though most loop regions do not show high sequence similarity among aquaglyceroporins, loop E is highly conserved in aquaglyceroporins, but not in members of the homologous aquaporins. Specifically, a tryptophan residue is extremely conserved within this loop. We have investigated the role of this residue (Trp219) that deeply protrudes into the protein and potentially interacts with adjacent loops, using the E. coli aqualgyeroporin GlpF as a model. Replacement of Trp219 affects the activity of GlpF and impairs the stability of the tetrameric protein. Furthermore, we have id…

Squaric Acid Mediated Synthesis and Biological Activity of a Library of Linear and Hyperbranched Poly(Glycerol)-Protein Conjugates

2012

Polymer-protein conjugates generated from side chain functional synthetic polymers are attractive because they can be easily further modified with, for example, labeling groups or targeting ligands. The residue specific modification of proteins with side chain functional synthetic polymers using the traditional coupling strategies may be compromised due to the nonorthogonality of the side-chain and chain-end functional groups of the synthetic polymer, which may lead to side reactions. This study explores the feasibility of the squaric acid diethyl ester mediated coupling as an amine selective, hydroxyl tolerant, and hydrolysis insensitive route for the preparation of side-chain functional, …

Gold Nanoparticles Coated with a Thermosensitive Hyperbranched Polyelectrolyte: Towards Smart Temperature and pH Nanosensors

2008

Specific stress-induced storage of trehalose, glycerol and D-arabitol in response to oxidative and osmotic stress in Candida albicans.

2012

Candida albicans exponential yeast cells are able to face environmental challenges by mounting a rapid and efficient "general stress response". Here we show that one of the main components of this response consists of the intracellular protective accumulation of the non-reducing disaccharide trehalose and two polyols, glycerol and D-arabitol, an accumulation that occurs in a stress-specific dependent manner. Thus, oxidative exposures promoted a marked increase in both trehalose and D-arabitol in the wild type strain, RM-100, whereas the glycerol content remained virtually unaffected with respect to basal levels. In contrast, osmotic challenges induced the significant storage of glycerol acc…

The yeast osmosensitive mutant fps1Δ transformed by the cauliflower BobTIP1;1 aquaporin withstand a hypo-osmotic shock

2005

AbstractOsmoregulation plays an important role in cellular responses to osmotic stress in plants and in yeast. Aquaporins contribute to osmotic adjustment by facilitating transport of water or solutes across membranes. The tonoplastic water channel BobTIP1;1 (original name BobTIP26-1) genes are upregulated during dessication stress in cauliflower meristematic tissue. To investigate the physiological importance of BobTIP1;1, we expressed it in a Saccharomyces cerevisiae osmosensitive mutant fps1Δ. We showed that the defect in the yeast glycerol plasma membrane transporter is complemented by a plant cDNA encoding the aquaporin BobTIP1;1 which is localized in the vacuolar membrane of the compl…

Molecular and enological characterization of a natural Saccharomyces uvarum and Saccharomyces cerevisiae hybrid

2015

Available online 17 March 2015

Cytotoxicity and chemosensitizing activity of amphiphilic poly(glycerol)-poly(alkylene oxide) block copolymers.

2014

All polymeric chemosensitizers proposed thus far have a linear poly(ethylene glycol) (PEG) hydrophilic block. To testify whether precisely this chemical structure and architecture of the hydrophilic block is a prerequisite for chemosensitization, we tested a series of novel block copolymers containing a hyperbranched polyglycerol segment as a hydrophilic block (PPO-NG copolymers) on multi-drug-resistant (MDR) tumor cells in culture. PPO-NG copolymers inhibited MDR of three cell lines, indicating that the linear PEG can be substituted for a hyperbranched polyglycerol block without loss of the polymers' chemosensitizing activity. The extent of MDR reversal increased with the polymers affinity…

Phosphonylation Controls the Protein Corona of Multifunctional Polyglycerol-Modified Nanocarriers.

2018

Nanocarriers are a platform for modern drug delivery. In contact with blood, proteins adsorb to nanocarriers, altering their behavior in vivo. To reduce unspecific protein adsorption and unspecific cellular uptake, nanocarriers are modified with hydrophilic polymers like poly(ethylene glycol) (PEG). However, with PEG the attachment of further functional structures such as targeting units is limited. A method to introduce multifunctionality via polyglycerol (PG) while maintaining the hydrophilicity of PEG is introduced. Different amounts of negatively charged phosphonate groups (up to 29 mol%) are attached to the multifunctional PGs (Mn 2-4 kg mol-1 , Ð < 1.36) by post-modification. PGs are …

Effect of plasticizers (water and glycerol) on the diffusion of a small molecule in iota-carrageenan biopolymer films for edible coating application.

2006

Translational diffusion of a fluorescein probe has been measured in iota-carrageenan edible films containing different amounts of glycerol (0, 15, 30, and 45%), using fluorescence recovery after photobleaching (FRAP) experiments. The effects of this plasticizer as well as the plasticizing effect of water on the diffusion of fluorescein have been studied in this edible coating mainly composed of natural biopolymer. Diffusion coefficients of about 10(-13) m2 s(-1) have been measured in these films for water activity (aw) lower than 0.7. Above this water content threshold, fluorescein translational diffusion coefficient increases up to 10(-12) m2 s(-1). Another interesting information obtained…