title: Di-, tri-, and tetrapeptide sequences in haptoglobin. Contribution to understanding of haptoglobin structure.
abstract: Amino acid sequences of haptoglobin and 11 proteins related and unrelated to haptoglobin were resolved into overlapping di-, tri-, and tetrapeptides. Comparison of the obtained peptides confirmed the existence of homology between haptoglobin and the family of serine proteases. The homology with light chain of immunoglobulins was relatively weak. A surprising similarity with concanavalin A was found. Tetrapeptide beta-turns (chain reversals), characterized by Chou & Fasman (1977, J. Mol. Biol., 115, 135-175) were compared with similar structures in light (alpha) and heavy (beta) subunits of haptoglobin.
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D006242:Haptoglobins; D009842:Oligopeptides / Q000032:analysis*; D011487:Protein Conformation
chemical_list: D006242:Haptoglobins; D009842:Oligopeptides