Highly purified ceruloplasmin messenger RNA from rat liver. Physico-chemical and functional characteristics.

Highly purified ceruloplasmin mRNA was isolated from rat liver polyribosomes. The molecular weight of ceruloplasmin mRNA is in a range from 1.05 to 1.25 · 106 daltons which is large enough to code for a putative precursor of ceruloplasmin (∼700 amino acids). Ceruloplasmin mRNA contains 3′-terminal poly(A) the length of which varies from 38 to 165 nucleotides. The 5′-end of ceruloplasmin mRNA is blocked with confronting m7G residue which is a component of cap I (m7G5′ppp5′XmpAp). The addition of ceruloplasmin mRNA to wheat-germ cell-free system programmed the synthesis of a product that was largely precipitated by anti-ceruloplasmin immunoglobulins. The translation product was homogeneous in polyacrylamide gel-sodium dodecylsulfate electrophoresis. Cell-free translation of ceruloplasmin mRNA was sensitive to inhibition by cap analogue.