Sequential volume changes on a small sample by density.
A procedure is described for generating a sequence of volume changes by density on the same sample of a solution. The entire volume-change profile over the reactant concentration range of interest can be accomplished with 0.1-0.2 mumol of a protein in 100 microliters of sample. The calcium-binding proteins, calmodulin and skeletal troponin-C, were employed to determine the volume increases attending the sequential addition of calcium ions. Both volume-change profiles exhibited nonlinear increases over the first four equivalents of calcium ion added.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D002417:Cattle; D008832:Microchemistry; D011817:Rabbits; D012996:Solutions; D013816:Thermodynamics; D014336:Troponin / Q000378:metabolism; D019209:Troponin C
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D012996:Solutions; D014336:Troponin; D019209:Troponin C; D002118:Calcium