Documents about Sodium Dodecyl

  • 7 Pages

    Spring 2003 Lecture 11 shorter pdf

    Purdue, CHM 333

    Excerpt: ... rge 63 CHM333 LECTURES 11: 2/10/03 Cation Exchange Separation by charge Beads with a negative charge SPRING 2003 Professor Christine Hrycyna Increased salt concentration to weaken electrostatic interactions. Change of pH to pH > pI (protein becomes negatively charged) Overall positive charge. Proteins have patches of positive charge Monitoring of proteins during chromatography UV absorbance is monitored dependent upon Trp, Tyr, Phe if protein is an enzyme, its activity can be monitored Electrophoresis separates components based upon their charge and/or size Polyacrylamide gel electrophoresis (PAGE) Proteins vary widely in their charge, size and even shape positive, negative or neutral at pH 7 spheres, rods, or embedded in membranes Use sodium dodecyl sulfate (SDS) to eliminate migration effects due to charge or shape SDS (negatively charged detergent) denatures proteins and binds to hydrophobic regions of the polypeptide Result: imparts a uniform charge/mass ratio ...

  • 9 Pages

    lec09-Detecting Folding Intermediates

    MIT, BIOL 7.88

    Excerpt: ... gents: Globular proteins can be denatured with a wide variety of agents: Heat o Denatured chains usually partially structured and aggregated (treatment with additional denaturing agents causes further changes). o Often not reversible on cooling outside very narrow set of conditions. o Covalent side reactions as temperature increases. Tropomyosin is an exception! pH o o o o Ionization of side chains breaking ion pairs, salt bridges Denatured chains highly charged: Increased charge density leads generalized electrostatic repulsion; Unfolded chain is structured Organic solvents o Benzene o Phenol o Trichloroethylene o Acetone o Ethanol o Chloroform o Acetonitrile Often neither native nor denatured state soluble in these solvents Difficult to compare conformations between immiscible solvents Some induce alpha-helicity, like TFE Detergents o sodium dodecyl sulfate Enormously important for analysis; denatured state binds 1.4gm/gram of detergent - denatured state is highly structured: Often is mi ...

  • 5 Pages

    Lab 24 Notes & Prelab

    SUNY Stony Brook, BIO 205

    Excerpt: ... Barbell Whiskers present Absent Absent Scale Type Scaleless Ctenoid Ctenoid Sarah Song BIO 205.33 April 29, 2008 Lab 24 Proteomics & Bioinformatics Notes Podcast Activities in order: 1, 3, 2 Activity 1: Inferring phylogenies from protein gels Purpose: Use techniques from proteomics to construct a cladogram of a few species of fish Like DNA lab Use an electrical field in a gel matrix to separate samples based on molecular weight Different from DNA lab Polyacrylamide instead of agarose Polyacrylamide: finer matrix higher resolving power Large fragments of DNA vs. proteins Need to make the charge of the sample uniform hot SDS Proteins can have different charges depending on their amino acids, unlike DNA which is all charged SDS: sodium dodecyl sulfate Detergent Unfolds the protein Disrupts all the hydrogen bonds maintaining the tertiary structure Applies a fairly uniform negative charge to the amino acid chain Binds to protein b ...

  • 12 Pages

    Naveena12052005

    Carnegie Mellon, STRUCTURE 9

    Excerpt: ... Naveena V.K. Yanamala Research Report # 5 2005-12-07 Structural Analysis Using NMR Research Goals: 1. NMR analysis of Peripherin Peptides 2. Comparision between 1H-15N HSQC Spectra of hegfr transmembrane-juxtamembrane domain (aa 615-686) with and without Sodium Dodecyl Sulfate 3. Comparision between 1H-15N HSQC Spectra of transducer in Natronobacterium pharaonis with and without Ammonium Sulphate, and analysis at different temparatures 1. NMR analysis of Peripherin Peptides Introduction The cGMP-gated channel of photoreceptors plays a central role in phototransduction by controlling the flow of cations into the outer segment in response to light-mediated changes in intracellular cGMP. The rod channel consists of two homologous subunits termed and that assemble into a heterotetrameric complex (1-4). Each subunit has a cyclic nucleotide-binding domain near the C terminus, six putative transmembrane domains designated S1-S6, and a pore segment between the S5 and S6 membrane-spanning segments. In addition, th ...

  • 4 Pages

    ps8a[1]

    Berkeley, MCB 100

    Excerpt: ... ease A, Mr = 13,700 D) RNA Polymerase, Mr=450,000 E) serum albumin, Mr=68,500 In gel filtration chromatography, larger molecules elute first. The answer is (B) immunoglobulin G. Q4. (i) By adding SDS ( sodium dodecyl sulfate) during the electrophoresis of proteins, it is possible to do which of the following? A) determine the amino acid composition of the protein. B) preserve the protein's native structure C) determine a protein's isoelectric point D) separate proteins primarily on the basis of molecular weight E) determine an enzyme's specific activity (ii) If gel electrophoresis were to be carried out without SDS, what complications might arise? Answer: (i) SDS coats the protein with a high negative charge density, and so the total charge on the protein reflects the molecular weight of the protein. Electrophoresis in the presence of SDS allows proteins of molecular weight. Answer = D (ii) if SDS were not used, two factors might complicate the analysis. First, the protein may remain folded, and its pass ...