Computer simulation for effect of Pr(III) on Ca(II) speciation in human interstitial fluid

Area of Science:

• Biochemistry
• Environmental Chemistry
• Computational Chemistry

Background:

• Human interstitial fluid plays a crucial role in cellular transport and homeostasis.
• Metal ion speciation is critical for understanding biological processes and potential toxicities.
• Lanthanide ions, like Praseodymium(III), can interact with essential biological ions such as Calcium(II).

Purpose of the Study:

• To develop a multiphase model for metal ion speciation in human interstitial fluid.
• To investigate the specific effects of Praseodymium(III) (Pr(III)) on Calcium(II) (Ca(II)) speciation.
• To understand the competitive binding interactions between Pr(III) and Ca(II) for ligands.

Main Methods:

• Construction of a multiphase model for metal ion speciation.
• Computational simulation of Pr(III) and Ca(II) interactions in interstitial fluid.
• Analysis of changes in Ca(II) species distribution under varying Pr(III) concentrations.

Main Results:

• Free Ca2+, [Ca(HCO3)], and [Ca(Lac)] were identified as the predominant Ca(II) species.
• Pr(III) competition led to increased percentages of free Ca2+, [Ca(Lac)], and [Ca(His)(Thr)H3].
• CaHPO4(aq) and [Ca(Cit)(His)H2] percentages decreased with increasing Pr(III).
• [Ca(HCO3)] and CaCO3(aq) initially increased then decreased as Pr(III) concentration surpassed 6.070 x 10-4 M.

Conclusions:

• Pr(III) significantly influences Ca(II) speciation in human interstitial fluid through ligand competition.
• The model provides insights into the complex interactions of lanthanides with essential divalent cations in biological systems.
• Understanding these interactions is vital for assessing the biological impact of Pr(III) exposure.