EDC Impressum & DSE

Electrophoresis
Development & Consulting
Dr. Hanspeter Schickle
Wolfgang Gstrein

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IEF of basic peptides

TSbasicPeptidesKlein

The more basic the gradient the unsharper the bands
(Peter Reiter, Gelita, Eberbach, Germany)

SDS of basic proteins and peptides

CollHydrolPH55SDSAgKlein

Basic proteins and peptides in SDS. Not good!
(Peter Reiter, Gelita, Eberbach, Germany)

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Basic Peptides

Basic peptides don’t like to be driven to their isoelectric points!
What they like is to have their maximal positive charges.
They also have no affinity to the negatively charged SDS-molecule.
So they should be separated in a native cathodal electrophoresis.
An acidic buffer will do this in a perfect way.

SDS of basic peptides

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PeptideSDSKlein

Basic peptides don’t like SDS
(Peter Reiter, Gelita, Eberbach, Germany)

Pfeil

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Native cathodal electrophoresis:
Basic peptides want to be separated in an acidic buffer. Here they are charged (+)!

pH 5.5 Collagen-Hydrolysate

Acidic buffer = cathodal electrophoresis
(Peter Reiter, Gelita, Eberbach, Germany)

5-7 kD

11 kD

 3 kD

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In native electrophoresis you will have no relation to mol-weight!
Double dimensional electrophoresis shows this.

First dimension = native cathodal electrophoresis
Second dimension = SDS-electrophoresis

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 <------------- cathodal native electrophoresis

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Mai 30, 2018

Native cathodal electrophoresis:
Basic peptides / proteines of E.coli

pH5.5 EColi

Acidic buffer = cathodal electrophoresis

DoubleNativeFalschfarben#2Klein

SDS-electrophoresis 

100 kD

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50 kD

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10 kD

If SDS shows no good results as second dimension:
Double Native Electrophoresis
First dimension = IPG-strip pH 7-11, 11 cm
Second dimension = cathodal native electrophoresis
Visualization: Hot Coomassie or Semi-Colloidal Coomassie

pH 7

 <------------- IPG-strip 7-11 ----------->

pH 11

Double Native 6-11; pH 5.5

Basic peptides / proteins of E.coli in double native electrophoresis
Molweights are not relative to their migration speeds.

Native cathodal electrophoresis 

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