Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The study addressed the general problem of fractionating cell envelopes in order to isolate the outer membranes of gram-negative bacteria. Whereas the cells are normally transformed into spheroplasts prior to disintegration and membrane separation, Serratia marcescens was found to be resistant to spheroplast formation using the procedures available, which were originally developed for Escherichia coli. An efficient technique for spheroplasting S. marcescens was therefore developed; this comprised combining osmotic shock and lysozyme-EDTA treatment of sucrose-conditioned cells. Spheroplasting efficiency and the amount of outer membrane protein recovered were highly dependent on the spheroplasting technique used. Separation of the outer and inner membranes was performed by two methods, isopyenic centrifugation and selective detergent solubilization with Sarkosyl. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the analysis of specific inner membrane marker enzymes revealed that the protein obtained by detergent solubilization was much purer than that obtained by isopycnic centrifugation. The outer membrane isolated accounted for 60% of the envelope proteins and had a buoyant density of 1.2502 g/cm3. The protein profile of the outer membrane determined by SDS-PAGE resolved into 12 distinct protein bands, 3 of which represented major proteins.
 ...
PMID:Isolation and characterization of the outer membrane proteins of Serratia marcescens W225. 825 Feb 25

When isolating proteins from complex biological material by immunosorption, the nonspecific binding and elution of other proteins present in much larger concentrations than the target protein are often a general problem, preventing the isolation of a pure protein. To improve this situation we have developed a new indirect immunosorption method, which makes use of a digoxigenylated anti-analyte antibody. This antibody is linked to streptavidin-coated magnetic beads via a biotinylated anti-digoxigenin antibody. After binding of the analyte to the affinity matrix, the complex composed of analyte and digoxigenylated anti-analyte antibody is specifically eluted with a solution of digoxigenin-lysine at pH 7.3. Coelution of nonspecifically bound proteins was highly reduced as revealed by SDS-PAGE when compared to the acidic eluates of the direct immunosorption. The efficiency of the indirect immunosorption method was demonstrated with the isolation of free prostate-specific antigen (PSA) and PSA/alpha(1)-antichymotrypsin complex from human serum and subsequent analysis of the intact proteins by SDS-PAGE and MALDI-TOF-mass spectrometry.
 ...
PMID:Purification of prostate-specific antigen from human serum by indirect immunosorption and elution with a hapten. 1045 4

A novel preparation for polyethylene glycol (PEG) derivatives and chromatographic separation procedure of the PEGylated recombinant human granulocyte colony-stimulating factor (rhG-CSF) were designed to evaluate the reproducibility and scalability at large laboratory-scale level. The new "PEG-pellet" PEGylation mode was successfully applied to control the pH fluctuation during the conjugation reaction, a general problem in traditional liquid-phase conjugation mode. Moreover, two consecutive ion-exchange chromatography steps were successfully used to separate and purify the PEGylated rhG-CSF. Cation-exchange chromatography was firstly applied to separate PEGylated rhG-CSF from intact rhG-CSF, followed by anion-exchange chromatography to obtain individual PEG-rhG-CSF species (mono-, di- and tri-PEGylated rhG-CSF) and remove the excess free PEG. Furthermore, the molecular weight of individual PEGylated rhG-CSF was identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and SDS-PAGE, and cell proliferation activity in vitro was detected by MTT assay using NFS-60 cell.
 ...
PMID:Reproducible preparation and effective separation of PEGylated recombinant human granulocyte colony-stimulating factor with novel "PEG-pellet" PEGylation mode and ion-exchange chromatography. 1590 87