Purification and characterization of winter flounder antifreeze peptide messenger ribonucleic acid

Publisher Website
Google Scholar
Abstract
The serum of winter flounder contains a group of small antifreeze peptides which lower the freezing point of their body fluids during the winter months. The poly(A)-containing mRNA coding for these peptides was isolated from livers of the winter specimens. When the isolated antifreeze mRNA was analyzed by denaturing polyacrylamide gel electrophoresis, at least 2 distinct bands .apprx. 450 nucleotides in length are visible. In a wheat germ cell-free protein synthetic system these mRNA direct the synthesis of small peptides which can be precipitated by antisera against purified winter flounder antifreeze peptides. Full-length c[complementary]DNA was synthesized from the isolated antifreeze mRNA by avian myeloblastosis virus reverse transcriptase. From the RNA excess hybridization kinetic analysis, there are probably 3 different mRNA coding for the antifreeze peptides. Using the radioactive cDNA probe, it was estimated that 1% of the total RNA in the liver of a Jan. specimen is antifreeze mRNA. RNA from a summer specimen showed no significant hybridization even at high concentrations of RNA. The control of antifreeze peptide biosynthesis relies at least in part on the synthesis or degradation of translatable mRNA.