{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T12:13:40Z","timestamp":1788437620922,"version":"build-2803163510"},"reference-count":36,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,3,30]],"date-time":"2022-03-30T00:00:00Z","timestamp":1648598400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004586","name":"Funda\u00e7\u00e3o Carlos Chagas Filho de Amparo \u00e0 Pesquisa do Estado do Rio de Janeiro","doi-asserted-by":"publisher","award":["#110.198-13; #210.003\/2018"],"award-info":[{"award-number":["#110.198-13; #210.003\/2018"]}],"id":[{"id":"10.13039\/501100004586","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Brazilian Council for Scientific Research","award":["#467.488.2014-2; #301744\/2019-0"],"award-info":[{"award-number":["#467.488.2014-2; #301744\/2019-0"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>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\u2013H7), and five were described for Hb (Hb1\u2013Hb5) 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\u2013H7 peptide sequences, but other residues may also play an important role. Molecular docking analysis demonstrated Hx\u2019s association with the \u03b2-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.<\/jats:p>","DOI":"10.3390\/ijms23073789","type":"journal-article","created":{"date-parts":[[2022,3,30]],"date-time":"2022-03-30T21:22:14Z","timestamp":1648675334000},"page":"3789","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["New Insights into Hemopexin-Binding to Hemin and Hemoglobin"],"prefix":"10.3390","volume":"23","author":[{"given":"Guilherme C.","family":"Lechuga","sequence":"first","affiliation":[{"name":"Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Neglected Population Diseases (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"},{"name":"Laboratory of Epidemiology and Molecular Systematics (LESM), Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paloma","family":"Napole\u00e3o-P\u00eago","sequence":"additional","affiliation":[{"name":"Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Neglected Population Diseases (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"},{"name":"Laboratory of Epidemiology and Molecular Systematics (LESM), Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2752-0009","authenticated-orcid":false,"given":"Carlos M.","family":"Morel","sequence":"additional","affiliation":[{"name":"Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Neglected Population Diseases (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David W.","family":"Provance","sequence":"additional","affiliation":[{"name":"Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Neglected Population Diseases (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"},{"name":"Laboratory of Epidemiology and Molecular Systematics (LESM), Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2172-656X","authenticated-orcid":false,"given":"Salvatore G.","family":"De-Simone","sequence":"additional","affiliation":[{"name":"Center for Technological Development in Health (CDTS), National Institute of Science and Technology for Innovation on Neglected Population Diseases (INCT-IDPN), FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"},{"name":"Laboratory of Epidemiology and Molecular Systematics (LESM), Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil"},{"name":"Department of Cellular and Molecular Biology, Biology Institute, Federal Fluminense University, Niter\u00f3i 24020-141, RJ, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1089\/104454902753759717","article-title":"Hemopexin: Structure, function, and regulation","volume":"21","author":"Tolosano","year":"2002","journal-title":"DNA Cell Biol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/S0009-8981(01)00586-1","article-title":"Hemopexin: A review of biological aspects and the role in laboratory medicine","volume":"312","author":"Delanghe","year":"2001","journal-title":"Clin. 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