IgG molecule - molecular weight (Jul/28/2007 )

i need to know the basic of the IgG molecule.i know its molecular weight but i need to know
1.wht will happen whn it is run in SDS page ,how manybands i get .
2.how many bands in native gel,i
3.ts stability and its isoforms
4.whn v digested with enzymes for eg papain wht will happen i need to know different enzymes and its action on IgG
5.why protein A-agarose is used as affinity column.

plz let me know with reason.

thanks in advance.
nishanth.

i need to know the basic of the IgG molecule.i know its molecular weight but i need to know
1.wht will happen whn it is run in SDS page ,how manybands i get .
2.how many bands in native gel,i
3.ts stability and its isoforms
4.whn v digested with enzymes for eg papain wht will happen i need to know different enzymes and its action on IgG
5.why protein A-agarose is used as affinity column.

plz let me know with reason.

thanks in advance.
nishanth.

Dear Nishanth,
Here is some answers to your questions.

1.the structure of the Antibody will be broken when you run a Reducing gel. the disulfied bonds between the heavy and light chain moolecules will broken and it they will separate into 4 bands. but you will able to see only 2 bands on gel.one is at 50Kd and Other is at 25Kd.So at each position i mean at 50 kd position there are 2 heavy chains and at 25 kd also there are 2 bands(because of same molecular weight you will see only one band at that positions).

2 you will get only one if you run a native gel because you are not breaking the disulfide bonds.you will get only one band at 150Kd.

3.Most of the IgG molecules are stable at Room temperature for some time. but keeping at cold temperatures will maintian the Antibody conformation for long term storage -20 is good (6 months) still more -70c is (more than a year) good option.

Comming to Isoforms there are 4 forms available.IgG1, IgG2,IgG3,And IgG4

4.when you digest with papin it will degraded into peptide molecules.refer enzyme actions on Antibody in any immunology book

5.you can use Protein G also for purification of IgG. the FC Portion of the Anitbody molecule will show more affinity towards the protein A .since the resin is couple with staphlococus membrane protein(called as A protein) Antibody will go and bind on to the resin.



i hope i have given a meaningful answeres to your questions.Please correct me if iam wrong

a waiting for your reply
take care

SudhakarMutyala
Sudhakar8@gmail.com[size="4"][/size]