Differences in C-terminal amino acid sequences between erythrocyte and liver cytochrome b5 isolated from pig and human. Evidence for two tissue-specific forms of cytochrome b5.
Two forms of cytochrome b5, a soluble erythrocyte form and a membrane-bound liver form, were purified from pig and human, and structural differences between them were analyzed. Porcine and human erythrocyte cytochrome b5 consisted of 97 amino acid residues and contained the same catalytic domain structure (residues 1-96) as that of the corresponding liver cytochrome b5, but had one amino acid replacement at the C-terminus (residue 97). These results suggest that erythrocyte cytochrome b5 is not derived from the liver protein by proteolysis but a translational product from another distinct mRNA of cytochrome b5.
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003573:Cytochrome b Group / Q000032:analysis*; D015786:Cytochromes b5; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology*; D013045:Species Specificity; D013552:Swine; D014357:Trypsin / Q000378:metabolism
D003573:Cytochrome b Group; D015786:Cytochromes b5; D014357:Trypsin