Actin cosedimentation experiments have worked very nicely for us in the past. It is fairly straightforward to do. Here is a brief method taking from one of our papers.

Actin co-sedimentation assays

Muscle G-actin was purified from rabbit skeletal muscle (Pardee and Spudich, 1982) and polymerised in 10 mM Tris, 50 mM NaCl, 100 mM ATP, 1 mM DTT, 1 mM MgCl2, pH 7.0. Assays were performed using 4mM talin and concentrations of F-actin ranging from 0 to 25 mM. The mixture was incubated for 60 min at room temperature and centrifuged at 100 000 r.p.m. for 30 min at 22oC using a Beckman Optima TM ultracentrifuge. Supernatants and pellets were analysed on 12% SDS–PAGE gels, stained using Coomassie blue and scanned. Protein levels in the pellet were determined using Image J software and normalised using talin loading controls (2 mM). Each mutant was analysed in triplicate.

Thanks Ben, could you give the paper reference as well?

Gingras AR, Bate N, Goult BT, Hazelwood L, Canestrelli I, Grossmann JG, Liu H, Putz NS, Roberts GC, Volkmann N, Hanein D, Barsukov IL and Critchley DR. (2008). The structure of the C-terminal actin-binding domain of talin. EMBO J. 27(2): 458-69

http://www.ncbi.nlm.nih.gov/pubmed/18157087

If you need any further technical details then just ask.

Cheers

Ben

Ben, could you also give me a suggestion on how could I check if my protein interacts with some plant polysaccharides such as cellulose/starch etc? is there an assay for the same?

I am sure there is an assay but, off the top of my head I am not sure which one, I would ask that as a separate question and I am sure someone will be able to advise you.

I already have, thanks!

Hi Madhurima, you can find a description how to measure binding to action by using MicroScale Thermophoresis (MST) in this paper:

"Functional Characterization of Human Myosin-18A and its Interaction with F-actin and GOLPH3"

http://www.jbc.org/content/early/2013/08/29/jbc.M113.497180.short

thanks Philipp