Impact of metal coordination and pH on the antimicrobial activity of histatin 5 and the products of its hydrolysis

Dalton Trans. 2024 Apr 30;53(17):7561-7570. doi: 10.1039/d4dt00565a.

Abstract

This work focuses on the relationship between the coordination chemistry and antimicrobial activity of Zn(II) and Cu(II) complexes of histatin 5 and the products of its hydrolysis: its N-terminal fragment (histatin 5-8) and C-terminal fragment (histatin 8). Cu(II) coordinates in an albumin-like binding mode and Zn(II) binds to up to 3 His imidazoles. The antimicrobial activity of histatins and their metal complexes (i) strongly depends on pH - they are more active at pH 5.4 than at 7.4; (ii) the complexes and ligands alone are more effective in eradicating Gram-positive bacteria than the Gram-negative ones, and (iii) Zn(II) coordination is able to change the structure of the N-terminal region of histatin 5 (histatin 5-8) and moderately increase all of the studied histatins' antimicrobial potency.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents / chemical synthesis
  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology
  • Coordination Complexes* / chemical synthesis
  • Coordination Complexes* / chemistry
  • Coordination Complexes* / pharmacology
  • Copper* / chemistry
  • Copper* / pharmacology
  • Gram-Negative Bacteria / drug effects
  • Gram-Positive Bacteria / drug effects
  • Histatins* / chemistry
  • Histatins* / pharmacology
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Microbial Sensitivity Tests*
  • Zinc* / chemistry
  • Zinc* / pharmacology

Substances

  • Histatins
  • Coordination Complexes
  • Copper
  • Zinc
  • Anti-Bacterial Agents
  • Anti-Infective Agents