Oligomeric protein - how to measure concentration? - (Apr/29/2008 )
If my enzyme is tetrameric and I measure the concentration - is this the concentration of monomer? And if so, do I just divide by 4 to get the conc of tetramer?
most protein determinations give you concentration by weight, not molarity, so it doesn't matter in what condition your protein is.
different methods to determine protein concentration target different sites, f.i. peptide bounds (Lowry, Biuret), ~280 nm (aromatic amino acids), argininyl, histidinyl and aromatic acids (CBB);
If the tetramer is intact during measurement, and therefore, some relevant target sites are masked, a measurement of tetramers may be lower than for dimers or monomers