The histidine-rich glycoprotein of serum has a domain rich in histidine, proline, and glycine that binds heme and metals

Biochemistry. 1985 Mar 12;24(6):1496-501. doi: 10.1021/bi00327a031.


Histidine-rich glycoprotein (HRG) from rabbit serum was digested with plasmin, reduced, and carboxymethylated, and the fragments produced were resolved by reverse-phase high-performance liquid chromatography. Several peptide fractions were obtained that contain unusually high contents of histidine, proline, and glycine. One His-Pro-Gly-rich peptide (apparent Mr 30 000) was obtained in sufficient yield and purity for further study. This peptide is 29 mol % histidine, 37% proline, and 16% glycine, indicating that most of these three amino acids are located in one region of HRG. The peptide contains 9% by weight carbohydrate and is devoid of tyrosine or tryptophan. The far-ultraviolet circular dichroism spectrum of the peptide has a minimum at 203 nm, indicating that the peptide contains polyproline II helical sections. The peptide represents a binding domain of HRG since it retains much of the ability of intact HRG to bind heme and metals including Zn2+, Ni2+, and Cu2+. As with the parent HRG molecule, interaction of the peptide with heme and metals is dependent on pH and intact histidine residues.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Circular Dichroism
  • Glycine / analysis
  • Heme / metabolism*
  • Histidine / analysis
  • Hydrogen-Ion Concentration
  • Metals / metabolism*
  • Molecular Weight
  • Proline / analysis
  • Proteins / analysis*
  • Proteins / metabolism
  • Rabbits


  • Metals
  • Proteins
  • histidine-rich proteins
  • Heme
  • Histidine
  • Proline
  • Glycine