Polypeptide composition of rat high density lipoprotein: characterization by SDS-gel electrophoresis

The histones synthesized by three different interspecies hybrid echinoid embryos have been examined. In all three crosses, the species-specific F1 histone of the paternal parent is found in the chromatin of the hybrid. These findings provide direct evidence for the involvement of newly transcribed mRNA in the synthesis of this protein. F1 histone is a unique protein in that it is the only paternal protein detected in these hybrids. The possibility that the synthesis of histones is controlled differently from that of other proteins is discussed.     

Cross-linking studies on the state of association of apo A-I and apo A-II from human HDL.

The technique of cross-linking with the bifunctional reagent dimethyl-suberimidate has been employed in the study of apolipoprotein association. Human apo A-I was found to undergo a concentration dependent self-association, with tetrameric and pentameric forms being the predominant polymeric species at concentrations of apo A-I between 0.5 and 1.1 mg/ml. However, apo A-II showed mainly monomer and dimer forms at concentrations ranging from 0.1 – 0.7 mg/ml. When these apolipoproteins were mixed, new cross-linked forms of molecular weight 45,000 and 73,500 became prominent. These molecular weights correspond to those of mixed polymers, indicating that these proteins interact in solution.