passages.id: BioInfer.d516.s1__text
passages.type: Sentence
passages.text: The very much lower affinity of profilin for modified actin explains the anomalous critical concentrations curves obtained for 5-10% pyrenyl-labeled actin in the presence of profilin and the apparently weak inhibition by profilin of the rate of filament elongation when polymerization is quantified by the increase in fluorescence of pyrenyl-labeled actin.