1You have a mixture of proteins with the following propertie

1.You have a mixture of proteins with the following properties:

Protein                  Molar Mass                pI

A                           45,000                         5.4

B                           13,400                         10.6    

C                           17,000                         7.0

D                           69,000                         4.8

E                            90,000                         5.9

Other factors aside, what order of emergence would you expect from these proteins run on the below methods of separation? (Note: order of elution is what protein elutes first from the column or with gel electrophoresis, what is the order of the proteins from the bottom of the gel to the top)

A cation exchange resin at pH 7.0 with a linear salt gradient?

A gel exclusion column

A SDS polyacrylamide gel electrophoresis

A isoelectric-focusing experiment indicate their distribution between the positive (+) and negative (-) ends of the gel.

Cathode (-) ---------------(+) Anode

Solution

1. A cation exchange resin at pH 7.0 with a linear salt gradient seperation will depend on the charge of a protein.

10.6 only can be eluted first.

2. gel exclusion chromatography 90000>69000>45000>17000>13400

3. in SDS PAGE 13400, 17000>45000>69000>90000

4. Cathode(-) 10.6 PI > 7> 5.9>5.4>4.8 anode(+)