Sodium Dodecyl Sulphate (SDS) is used while separating proteins by polyacrylamide gel electrophoresis because :
it binds to proteins and confers a uniform negative charge density thereby making them move during electrophoresis
SDS is an anionic detergent. In SDS-PAGE the protein is boiled with SDS (and usually a reducing agent), which unfolds it and coats the polypeptide chain with detergent molecules.
About 1.4 g of SDS binds per gram of protein, roughly one SDS molecule per two amino acid residues, so every polypeptide acquires a large negative charge that is proportional to its length. The intrinsic charge of the protein becomes negligible.
Because the charge-to-mass ratio is now nearly the same for all polypeptides, they all migrate towards the anode and the sieving action of the gel separates them only by size, which allows molecular-weight estimation.
Solubilization is a side effect, not the reason SDS is used for separation; SDS has no role in lowering buffer surface tension for the run; and far from stabilizing proteins, it denatures them.
Hence, it binds to proteins and confers a uniform negative charge density thereby making them move during electrophoresis.
Similar Questions
DNA is supercoiled state can be relaxed by an enzymatic process. Which enzyme catalyses relaxation of supercoiled DNA?
Adaptive radiation produced numerous lineages from reptiles during chordate evolution. One of the following gave rise to mammals:
Which one produces highest isotope effect?
Which one of the following conditions is true for parthenogenesis?
The urge to inhale in human being results from:
Which of the following is responsible for triggering formation of other enzymes?
Which of the following is critical for differentiation of bipotential gonads towards ovarian pathway?
The PCR technique that allows measuring of DNA amplification at each cycle of PCR rather than the end point detection is:
Abscisic acid responsive elements (ABREs) are over-represented in promoter of genes involved in ............
In humans pointed eyebrows are dominant over smooth eyebrows and downward pointed frontal hairline is dominant over continuous hairline. What phenotypic ratio would you expect in the offspring from a cross between an individual heterozygous for both genes and an individual homozygous recessive for both genes?
Important Questions from Mixed Topic (MH-SET)
.................... is a client server application that identifies each host on the internet with a unique user-friendly name.
Every OS has a ................ or .......... which primarily resides in the main memory of the computer to perform some of the basic functions of the OS.
(i) Kernel
(ii) Interface
(iii) Nucleus
(iv) Compiler
Codes:
Which of the following are referred to as low level language?
(i) Machine language
(ii) Assembly language
(iii) High level language
(iv) Natural language
Codes:
Match the following:
List I List II (a) New York Public Library (i) Shelv AR (b) Miami University Augmented Research Group (ii) Smart library (c) Oula University Library (iii) Wolf Walk (d) North Carolina State University (iv) Find the future Codes:
Which part of the QR code represents the encoded data?
