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Investigation of the hemoglobin alpha-chains of an Asiatic deer, the sika (Cervus nippon), was prompted by the heterogenity of alpha-chain gene loci in the Virginia white-tailed deer (Odocoileus virginianus). Although electrophoresis of hemoglobin chains from 10 sika revealed only a single alpha-chain band, peptide mapping demonstrated variations in the alpha-TPIII and alpha-TPIV peptides. Substitutions at positions 15, 20, and 22 produced a minimum of five alpha-chains; two possible additional chains could noy be proven because of inseparability of the whole alpha-chains. The most common chain contains Asp-15, Lys-20 and Pro-22 but in other chains glycine is present at position 15, Asx at position 20, and either serine or Asx at position 22. The probable explanation for the large number of alpha-chains is gene duplication which may have been produced by breedings between subspecies from different geographical areas. Comparison with the alpha-chain structure of the white-tailed deer suggests that the sika may have evolved from the lineage which produced the white tailed-deer after the alpha-chain genes of the latter species had duplicated. In addition, these data provide further examples of the unusual variability of this portion of the alpha-chain.

A methodological approach for comparative structural study of apolipoprotein B has been developed. Low-density lipoproteins from four human subjects were digested in three separate enzyme systems, utilizing trypsin, chymotrypsin and Staphylococcus aureus protease V8, each in the presence of 1% sodium dodecyl sulfate. The peptides were separated by electrophoresis on polyacrylamide gels in SDS; the stained gels were scanned spectrophotometrically to produce characteristic profiles. Comparison of the profiles revealed good reproducibility and a high degree of similarity among the different subjects. Of the four subjects studied, one subject had one apparent difference in the tryptic digest profile and also in the S. aureus protease V8 digest profile. The structural significance of these variations can be evaluated only after a larger number of subjects, including those presented here, have been examined; this study is now in preparation.