PAGE electrophoresis

[deleted801953]

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Just to be sure
Native page- Breaks no bonds/ structures

SDS page- breaks dimers or quaternary structures (only?) to form monomers

SDS page reducing- breaks oxidized covalent bonds (any examples aside from disulfide bonds?)

Any others for MCAT purposes?

Thank you!

 

[pretty_positron]

• Native PAGE (non-denaturing) - mobility determined by protein's charge and hydrodynamic size => used to separate mixtures
• SDS-PAGE (denaturing) - SDS is an anionic detergent that denatures 2° and non-disulfide-linked 3° structures; applies a (-) charge to each protein in proportion to mass => used for checking purity
• reducing - breaks disulfide linkages and disrupts 3° and 4° structures

Reagents:

B-mercaptoethanol - breaks disulfide bonds, unfolding 3° structure. However, this is reversible . Removal of this reagent causes reformation of disulfide bonds.

Urea - disrupts hydrogen bonds

*In proteins, 1° is always present. 3° can exist without 2°. Multiple bands indicate 4° as native forms.