Novel combinations of experimental and computational analysis tested on the binding of metalloprotoporphyrins to albumin

Jie Hu, Eduardo Hernandez Soraiz, Courtney N. Johnson, Borries Demeler, Lorenzo Brancaleon

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

The evidence that Human Serum Albumin (HSA) binds metal ions and organometallic compounds has generated interest in its physiological role as a metalloprotein and as a vehicle for synthetic biology applications (e.g., synthetic blood and solar energy conversion). HSA has been shown to bind metallo-porphyrins, however, the structural details of such interactions are available only for the HSA:heme complex. A typical challenge for studying the interaction of proteins with metalloporphyrins is the poor solubility of the ligands that affect the characterization the complexes. The manuscript shows that a combination of dialysis and centrifugation yields aqueous solutions that contain >90% HSA:porphyrin complexes and virtually eliminate aggregated ligands. The removal of aggregates increases the quality of the optical spectroscopy data which, in turn, yield more accurate binding constants (~0.1 and 2.1 × 10 6 M −1 ) and reveal FRET between Trp214 and the porphyrins. The Trp-porphyrin distance was estimated to be within the 28–34 Å range and was used to guide the search of binding sites through a novel feedback approach with docking simulations. Results suggest while some protoporphyrins (metal-free, Fe(III)PPIX and Mg(II)PPIX) bind HSA at the heme site, others (Zn(II)PPIX, Mn(III)PPIX and Sn(IV)PPIX) are more likely to bind the Cys34.

Original languageEnglish (US)
Pages (from-to)445-457
Number of pages13
JournalInternational Journal of Biological Macromolecules
Volume134
DOIs
StatePublished - Aug 1 2019

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Economics and Econometrics
  • Energy(all)

Fingerprint Dive into the research topics of 'Novel combinations of experimental and computational analysis tested on the binding of metalloprotoporphyrins to albumin'. Together they form a unique fingerprint.

  • Cite this