Representative LDS-PAGE analyses of soluble and insoluble proteins derived from three different C. nemoralis shell-pigment fractions (yellow, orange and brown). A. Soluble proteins. B. Insoluble proteins. The most striking difference between these fractions was the abundance of the proteins present in the yellow-soluble and orange-soluble fractions relative to the brown-soluble fraction. This pattern is reversed in the acid-insoluble fractions.