New Insights into Hemopexin-Binding to Hemin and Hemoglobin

Hemopexin (Hx) is a plasma glycoprotein that scavenges heme (Fe(III) protoporphyrin IX). Hx has important implications in hemolytic disorders and hemorrhagic conditions because releasing hemoglobin increases the labile heme, which is potentially toxic, thus producing oxidative stress. Therefore, Hx has been considered for therapeutic use and diagnostics. In this work, we analyzed and mapped the interaction sequences of Hx with hemin and hemoglobin. The spot-synthesis technique was used to map human hemopexin (P02790) binding to hemin and human hemoglobin. A library of 15 amino acid peptides with a 10-amino acid overlap was designed to represent the entire coding region (aa 1-462) of hemopexin and synthesized onto cellulose membranes. An in silico approach was taken to analyze the amino acid frequency in the identified interaction regions, and molecular docking was applied to assess the protein-protein interaction. Seven linear peptide sequences in Hx were identified to bind hemin (H1-H7), and five were described for Hb (Hb1-Hb5) interaction, with just two sequences shared between hemin and Hb. The amino acid composition of the identified sequences demonstrated that histidine residues are relevant for heme binding. H105, H293, H373, H400, H429, and H462 were distributed in the H1-H7 peptide sequences, but other residues may also play an important role. Molecular docking analysis demonstrated Hx's association with the β-chain of Hb, with several hotspot amino acids that coordinated the interaction. This study provides new insights into Hx-hemin binding motifs and protein-protein interactions with Hb. The identified binding sequences and specific peptides can be used for therapeutic purposes and diagnostics as hemopexin is under investigation to treat different diseases and there is an urgent need for diagnostics using labile heme when monitoring hemolysis.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:23

Enthalten in:

International journal of molecular sciences - 23(2022), 7 vom: 30. März

Sprache:

Englisch

Beteiligte Personen:

Lechuga, Guilherme C [VerfasserIn]
Napoleão-Pêgo, Paloma [VerfasserIn]
Morel, Carlos M [VerfasserIn]
Provance, David W [VerfasserIn]
De-Simone, Salvatore G [VerfasserIn]

Links:

Volltext

Themen:

42VZT0U6YR
4QD397987E
743LRP9S7N
9013-71-2
Ferric Compounds
Heme
Hemin
Hemoglobin
Hemoglobins
Hemopexin
Histidine
Journal Article
Protein-protein binding

Anmerkungen:

Date Completed 13.04.2022

Date Revised 03.11.2023

published: Electronic

Citation Status MEDLINE

doi:

10.3390/ijms23073789

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM339387556