The amino acid sequence of human liver apoferritin

The protein component of the iron storage molecule, ferritin, contains 24 subunits in form of a hollow shell known as apoferritin. The amino acid sequence has been determined for apoferritin subunits from human liver. The sequence comprises 174 amino acids giving an Mr of 19 900. It shows extensive homology with the primary structures of apoferritins from human and horse spleen and from rat liver. Sequence substitutions are discussed in relation to the known three-dimensional structure of horse spleen apoferritin. Evidence for a second minor sequence in human liver apoferritin is presented.