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Current Protocols in Protein Science Aug 2015Quantitating relative levels of detergent present in protein preparations or samples derived from biological material, such as tissue or body fluids, is important...
Quantitating relative levels of detergent present in protein preparations or samples derived from biological material, such as tissue or body fluids, is important because the presence of detergent may affect downstream analyses as well as protein structure/function. Especially because sample volumes, analysts' available time, and other resources may be limited, a method that consumes little sample and that is rapid and simple is needed for detergent analysis. It would also be preferable to have a method that is generally applicable across many aliphatic chain-containing molecules with many different physical properties. In this unit, methods are described for analyzing detergents and proteins in detergent-protein mixtures using mid-infrared (MIR) spectroscopy. A protocol is also included for efficient removal of unbound detergents from a protein sample accompanied by MIR-based monitoring of both detergent and protein content. This rapid monitoring of sample preparation during the workflow enables users to make timely decisions about sample preparation strategies that maximize both analyte purity and yield.
Topics: Detergents; Membrane Proteins; Spectrophotometry, Infrared
PubMed: 26237674
DOI: 10.1002/0471140864.ps2912s81 -
Nursing Times Jan 1962
Topics: Biomedical Research; Dermatitis; Dermatitis, Contact; Detergents; Humans
PubMed: 14496684
DOI: No ID Found -
Biophysical Journal Dec 2012Detergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and...
Detergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and fine-tuning detergent properties can be crucial for obtaining structural information of intact and functional transmembrane proteins. To systematically investigate the influence of the detergent concentration and acyl-chain length on the stability of a transmembrane protein structure, the stability of the human glycophorin A transmembrane helix dimer has been analyzed in lyso-phosphatidylcholine micelles of different acyl-chain length. While our results indicate that the transmembrane protein is destabilized in detergents with increasing chain-length, the diameter of the hydrophobic micelle core was found to be less crucial. Thus, hydrophobic mismatch appears to be less important in detergent micelles than in lipid bilayers and individual detergent molecules appear to be able to stretch within a micelle to match the hydrophobic thickness of the peptide. However, the stability of the GpA TM helix dimer linearly depends on the aggregation number of the lyso-PC detergents, indicating that not only is the chemistry of the detergent headgroup and acyl-chain region central for classifying a detergent as harsh or mild, but the detergent aggregation number might also be important.
Topics: Amino Acid Sequence; Cell Membrane; Detergents; Dose-Response Relationship, Drug; Glycophorins; Humans; Hydrophobic and Hydrophilic Interactions; Lysophosphatidylcholines; Micelles; Molecular Sequence Data; Protein Multimerization; Protein Structure, Secondary
PubMed: 23260047
DOI: 10.1016/j.bpj.2012.11.004 -
Revista Latino-americana de Enfermagem 2019to evaluate the potential contamination of enzymatic detergent from its reuse and to identify the microbiological profile in the solution used to clean gastrointestinal...
OBJECTIVE
to evaluate the potential contamination of enzymatic detergent from its reuse and to identify the microbiological profile in the solution used to clean gastrointestinal endoscopic devices.
METHOD
cross-sectional study based on microbiological analysis of 76 aliquots of 19 different enzymatic detergent solutions used to clean endoscopic devices. The aliquots were homogenized, subjected to Millipore® 0.45 µm membrane filtration and the presumptive identification of microorganisms was performed by biochemical-physiological methods according to previously established specific bacterial groups that are of clinical and epidemiological relevance.
RESULTS
the mean values, as well as the standard deviation and the median, of the enzymatic detergent microbial load increased as the solution was reused. There was a significant difference between the means of after first use and after fifth reuse. A total of 97 microorganisms were identified, with predominance of the coagulase-negative Staphylococcus, Pseudomonas spp., Klebsiella spp., Enterobacter spp. genus, and Escherichia coli species.
CONCLUSION
the reuse of the enzymatic detergent solution is a risk to the safe processing of endoscopic devices, evidenced by its contamination with pathogenic potential microorganisms, since the enzymatic detergent has no bactericidal property and can contribute as an important source for outbreaks in patients under such procedures.
Topics: Bacterial Load; Cross-Sectional Studies; Detergents; Disease Transmission, Infectious; Equipment Contamination; Gastroscopes; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Infection Control
PubMed: 31826156
DOI: 10.1590/1518-8345.3101.3211 -
Langmuir : the ACS Journal of Surfaces... Dec 2022Mixed micellar drug delivery systems for poorly soluble active pharmaceutical ingredients (APIs) are easy to produce and long-term stable, because they represent...
Mixed micellar drug delivery systems for poorly soluble active pharmaceutical ingredients (APIs) are easy to produce and long-term stable, because they represent equilibrium structures. However, their fate after intravenous injection is still largely unknown. Once injected into the bloodstream, they can potentially convert to vesicles or disappear altogether, with both API and excipients being picked up by blood components. Our study aimed at reducing the gap between the good, quantitative understanding of aqueous glycocholate (GC)-lecithin dispersions alone and the highly complex situation in the blood. To this end, we extended the pseudophase model previously established for lipid-detergent dispersions to include the detergent-binding protein albumin as another component. The model predicted a quaternary phase diagram with planar phase boundaries defined by key parameters of the ternary subsystems, which were then determined by isothermal titration calorimetry. They include the aqueous GC concentration upon bilayer-micelle coexistence, 5.2 mM, the GC-to-lipid mole ratios in coexisting bilayers ( = 0.2) and micelles ( = 0.7), as well as the capacity of the albumin to bind 0.1 GC molecules with a dissociation constant of = 0.1 mM and 6 GC molecules with = 0.7 mM. Subsequent measurements in the quaternary system showed phase boundaries in good agreement with the model predictions. In addition, the critical micelle concentration of GC shows a minimal value (midpoint of transition) of 9.1 mM at the temperature of 24 °C where the demicellization enthalpy is zero. The demicellization process is accompanied by a heat capacity change of 29 cal/mol K. The model improves the understanding of the mixed micellar drug delivery systems. The success of the approach encourages including even more blood components, like lipoproteins, to a quantitative treatment.
Topics: Lipid Bilayers; Detergents; Micelles; Temperature; Thermodynamics
PubMed: 36480936
DOI: 10.1021/acs.langmuir.2c02234 -
Methods in Molecular Biology (Clifton,... 2019Denaturing, discontinuous electrophoresis in the presence of SDS has become a standard method for the protein scientist. However, there are situations where this method...
Denaturing, discontinuous electrophoresis in the presence of SDS has become a standard method for the protein scientist. However, there are situations where this method produces suboptimal results. In these cases electrophoresis in the presence of positively charged detergents like cetyltrimethylammonium bromide (CTAB) may work considerably better. Methods for electrophoresis and staining of such gels are presented.
Topics: Cations; Cetrimonium; Detergents; Electrophoresis; Proteins
PubMed: 30426413
DOI: 10.1007/978-1-4939-8793-1_12 -
Biochimie 1998The structure of the detergent, ocytyl hydroxyethylsufoxide (C8(HE)SO), bound to the OmpF porin from E coli (in the trigonal crystal form) has been determined by neutron... (Comparative Study)
Comparative Study
The structure of the detergent, ocytyl hydroxyethylsufoxide (C8(HE)SO), bound to the OmpF porin from E coli (in the trigonal crystal form) has been determined by neutron crystallography. Due to a dynamic exchange of detergent molecules with their environment they are not ordered on an atomic scale. The structure reported here is therefore at a resolution of approximately 16 A. The X-ray crystallographically determined structure of the protein provides a starting point for the neutron analysis in which the detergent is visualized primarily thanks to its high contrast against D2O. The structure shows the detergent to be located mainly in two areas. It forms toroidal annuli around each OmpF trimer, these annuli fusing to form a detergent belt surrounding a solvent filled column traversing the crystal. Those areas of the protein to which the detergent binds are formed almost exclusively of hydrophobic residues and form a band about 30 A high around the trimer. Its upper and lower bounds are defined by two bands of aromatic residues, tyrosines pointing away from the detergent belt and interacting with the polar headgroups while phenylalanines point inwards. This strongly suggests that the same areas define, in vivo, the location at which protein interacts with lipid. The hydrophobic moiety of detergent is also found mediating the hydrophobic protein-protein interactions at the interface between two trimers on the crystallographic two-fold axis.
Topics: Crystallization; Crystallography; Crystallography, X-Ray; Detergents; Escherichia coli; Models, Molecular; Neutrons; Porins; Sulfoxides
PubMed: 9782392
DOI: 10.1016/s0300-9084(00)80019-x -
Biologicals : Journal of the... Aug 2023Each process step in the manufacture of biological products requires expensive resources and reduces total process productivity. Since downstream processing of...
Each process step in the manufacture of biological products requires expensive resources and reduces total process productivity. Since downstream processing of biologicals is the main cost driver, process intensification is a persistent topic during the entire product life cycle. We present here one approach for the intensification of bioprocesses by applying on-column virus inactivation using solvent/detergent (S/D) treatment during ion-exchange chromatography. The established purification process of a recombinant protein was used as a model to compare key process parameters (i.e., product yield, specific activity, impurity clearance) of the novel approach to the standard process protocol. Additional wash and incubation steps with and without S/D-containing buffers were introduced to ensure sufficient contact time to effectively eliminate enveloped viruses and to significantly decrease the amount of S/D reagents. Comparison of key process parameters demonstrated equivalent process performance. To assess the viral clearance capacity of the novel approach, XMuLV was spiked as model virus to the chromatographic load and all resulting fractions were analyzed by TCID and RT-qPCR. Data indicates the inactivation capability of on-column virus inactivation even at 10% of the nominal S/D concentration, although the mechanism of viral clearance needs further investigation.
Topics: Detergents; Biological Products; Virus Inactivation; Solvents; Viruses
PubMed: 37516085
DOI: 10.1016/j.biologicals.2023.101693 -
Ecotoxicology and Environmental Safety Oct 1990Surfactants are high volume chemicals used primarily in detergent products and are found in natural waters. The toxic effects of representative surfactants on aquatic... (Review)
Review
Surfactants are high volume chemicals used primarily in detergent products and are found in natural waters. The toxic effects of representative surfactants on aquatic life have been determined and summarized in greater detail for animal test species than for aquatic vegetation. This paper summarizes the chronic toxicity levels for algae, an important trophic level in aquatic ecosystems. Toxic effects have been determined for a few commercially important surfactants and primarily for cultured freshwater algae under the controlled conditions of the laboratory where inhibition, and in some cases, stimulation have been observed. The reported toxicities of surfactants have varied widely over several orders of magnitude and the effect levels are compound and species-specific. Species sensitivity can vary as much as three orders of magnitude to the same surfactant and the effects of different surfactants on the same algal species can vary as much as four orders of magnitude. Therefore, data generalizations and extrapolations are difficult but anionic and nonionic surfactants and detergent builders are relatively non-toxic when compared to various cationic monoalkyl and dialkyl quaternary ammonium salts. Recent toxicity studies conducted in the field monitoring the effects of several surfactants used in commercial products on various structural and functional parameters of natural algal communities have shown toxicity to be less in many cases than that predicted from laboratory tests. Furthermore, the field-derived effect levels typically exceed the reported measured environmental levels of the corresponding surfactants indicating the likelihood of no impact. Additional field studies are needed to substantiate this trend for these and other commercially important surfactants particularly for natural saltwater algal assemblages for which the toxicity data base is unavailable.
Topics: Detergents; Eukaryota; Risk; Surface-Active Agents
PubMed: 2276359
DOI: 10.1016/0147-6513(90)90052-7 -
Nature Protocols 2007The biological membrane is a complicated matrix wherein different lipid environments are thought to exist. The more ordered or raft environment has been perceived...
The biological membrane is a complicated matrix wherein different lipid environments are thought to exist. The more ordered or raft environment has been perceived biochemically accessible via its relative resistance to detergent. This paper outlines the protocols developed in our laboratory for the analysis of such detergent-resistant membranes (DRMs). We stress the fact that DRMs are artifactual in nature and should not be equivocated to lipid rafts, their usefulness being limited to assigning raft-association potential most convincingly when changes in DRM composition are induced by biochemically/physiologically relevant events. These protocols are completed in 1-2 d.
Topics: Animals; Cell Culture Techniques; Cell Fractionation; Detergents; Membrane Microdomains; Micelles; Solubility
PubMed: 17853872
DOI: 10.1038/nprot.2007.294