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?

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most protein determinations give you concentration by weight, not molarity, so it doesn't matter in what condition your protein is.

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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

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