{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,14]],"date-time":"2026-03-14T21:22:28Z","timestamp":1773523348744,"version":"3.50.1"},"reference-count":42,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2012,5,1]]},"abstract":"<jats:p>TTR (transthyretin) was found recently to possess proteolytic competency besides its well-known transport capabilities. It was described as a cryptic serine peptidase cleaving multiple natural substrates (including \u03b2-amyloid and apolipoprotein A-I) involved in diseases such as Alzheimer's disease and atherosclerosis. In the present study, we aimed to elucidate the catalytic machinery of TTR. All attempts to identify a catalytic serine residue were unsuccessful. However, metal chelators abolished TTR activity. Proteolytic inhibition by EDTA or 1,10-phenanthroline could be reversed with Zn2+ and Mn2+. These observations, supported by analysis of three-dimensional structures of TTR complexed with Zn2+, led to the hypothesis that TTR is a metallopeptidase. Site-directed mutagenesis of selected amino acids unambiguously confirmed this hypothesis. The TTR active site is inducible and constituted via a protein rearrangement resulting in ~7% of proteolytically active TTR at pH\u00a07.4. The side chain of His88 is shifted near His90 and Glu92 establishing a Zn2+-chelating pattern HXHXE not found previously in any metallopeptidase and only conserved in TTR of humans and some other primates. Point mutations of these three residues yielded proteins devoid of proteolytic activity. Glu72 was identified as the general base involved in activation of the catalytic water. Our results unveil TTR as a metallopeptidase and define its catalytic machinery.<\/jats:p>","DOI":"10.1042\/bj20111690","type":"journal-article","created":{"date-parts":[[2012,2,16]],"date-time":"2012-02-16T11:17:44Z","timestamp":1329391064000},"page":"769-778","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":43,"title":["Transthyretin is a metallopeptidase with an inducible active site"],"prefix":"10.1042","volume":"443","author":[{"given":"M\u00e1rcia\u00a0A.","family":"Liz","sequence":"first","affiliation":[{"name":"Nerve Regeneration Group, Instituto de Biologia Molecular e Celular \u2013 IBMC, 4150-180 Porto, Portugal"}]},{"given":"S\u00e9rgio\u00a0C.","family":"Leite","sequence":"additional","affiliation":[{"name":"Nerve Regeneration Group, Instituto de Biologia Molecular e Celular \u2013 IBMC, 4150-180 Porto, Portugal"}]},{"given":"Luiz","family":"Juliano","sequence":"additional","affiliation":[{"name":"Escola Paulista de Medicina, Universidade Federal de S\u00e3o Paulo, 04044-020 S\u00e3o Paulo, Brazil"}]},{"given":"Maria\u00a0J.","family":"Saraiva","sequence":"additional","affiliation":[{"name":"Molecular Neurobiology Group, Instituto de Biologia Molecular e Celular \u2013 IBMC, 4150-180 Porto, Portugal"},{"name":"ICBAS, Universidade do Porto, 4099-033 Porto, Portugal"}]},{"given":"Ana\u00a0M.","family":"Damas","sequence":"additional","affiliation":[{"name":"Molecular Structure Group, Instituto de Biologia Molecular e Celular \u2013 IBMC, 4150-180 Porto, Portugal"},{"name":"ICBAS, Universidade do Porto, 4099-033 Porto, Portugal"}]},{"given":"Daniel","family":"Bur","sequence":"additional","affiliation":[{"name":"Actelion Pharmaceuticals Ltd, 4123 Allschwil, Switzerland"}]},{"given":"M\u00f3nica\u00a0M.","family":"Sousa","sequence":"additional","affiliation":[{"name":"Nerve Regeneration Group, Instituto de Biologia Molecular e Celular \u2013 IBMC, 4150-180 Porto, Portugal"}]}],"member":"288","published-online":{"date-parts":[[2012,4,16]]},"reference":[{"key":"2021112217284830000_B1","doi-asserted-by":"crossref","first-page":"6796","DOI":"10.1016\/S0021-9258(19)42128-5","article-title":"The amino acid sequence of human plasma prealbumin","volume":"249","author":"Kanda","year":"1974","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B2","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1002\/humu.1132","article-title":"Transthyretin mutations in hyperthyroxinemia and amyloid diseases","volume":"17","author":"Saraiva","year":"2001","journal-title":"Hum. Mutat."},{"key":"2021112217284830000_B3","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1093\/brain\/75.3.408","article-title":"A peculiar form of peripheral neuropathy; familiar atypical generalized amyloidosis with special involvement of the peripheral nerves","volume":"75","author":"Andrade","year":"1952","journal-title":"Brain"},{"key":"2021112217284830000_B4","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/0022-2836(78)90368-6","article-title":"Structure of prealbumin: secondary, tertiary and quaternary interactions determined by Fourier refinement at 1.8 \u00c5","volume":"121","author":"Blake","year":"1978","journal-title":"J. Mol. Biol."},{"key":"2021112217284830000_B5","doi-asserted-by":"crossref","first-page":"6969","DOI":"10.1021\/bi800636q","article-title":"Quantification of the thermodynamically linked quaternary and tertiary structural stabilities of transthyretin and its disease-associated variants: the relationship between stability and amyloidosis","volume":"47","author":"Hurshman Babbes","year":"2008","journal-title":"Biochemistry"},{"key":"2021112217284830000_B6","doi-asserted-by":"crossref","first-page":"9123","DOI":"10.1021\/bi700607z","article-title":"Characterization of the binding of Cu(II) and Zn(II) to transthyretin: effects on amyloid formation","volume":"46","author":"Wilkinson-White","year":"2007","journal-title":"Biochemistry"},{"key":"2021112217284830000_B7","doi-asserted-by":"crossref","first-page":"9079","DOI":"10.1021\/bi050378f","article-title":"Cys-10 mixed disulfide modifications exacerbate transthyretin familial variant amyloidogenicity: a likely explanation for variable clinical expression of amyloidosis and the lack of pathology in C10S\/V30M transgenic mice?","volume":"44","author":"Zhang","year":"2005","journal-title":"Biochemistry"},{"key":"2021112217284830000_B8","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1016\/j.jmb.2008.07.029","article-title":"Structural insight into pH-induced conformational changes within the native human transthyretin tetramer","volume":"382","author":"Palaninathan","year":"2008","journal-title":"J. Mol. Biol."},{"key":"2021112217284830000_B9","doi-asserted-by":"crossref","first-page":"25832","DOI":"10.1074\/jbc.M109.017657","article-title":"Amyloidogenic potential of transthyretin variants: insights from structural and computational analyses","volume":"284","author":"Cendron","year":"2009","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B10","doi-asserted-by":"crossref","first-page":"3230","DOI":"10.1016\/S0021-9258(18)93118-2","article-title":"The interaction of thyroxine with human plasma prealbumin and with the prealbumin-retinol-binding protein complex","volume":"244","author":"Raz","year":"1969","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B11","doi-asserted-by":"crossref","first-page":"1039","DOI":"10.1126\/science.7754382","article-title":"Structure of a complex of two plasma proteins: transthyretin and retinol-binding protein","volume":"268","author":"Monaco","year":"1995","journal-title":"Science"},{"key":"2021112217284830000_B12","doi-asserted-by":"crossref","first-page":"1137","DOI":"10.1021\/cb100144v","article-title":"Retinol and retinol-binding protein stabilize transthyretin via formation of retinol transport complex","volume":"5","author":"Hyung","year":"2010","journal-title":"ACS Chem. Biol."},{"key":"2021112217284830000_B13","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/S0022-2275(20)32074-5","article-title":"Transthyretin in high density lipoproteins: association with apolipoprotein A-I","volume":"41","author":"Sousa","year":"2000","journal-title":"J. Lipid Res."},{"key":"2021112217284830000_B14","doi-asserted-by":"crossref","first-page":"21431","DOI":"10.1074\/jbc.M402212200","article-title":"Transthyretin, a new cryptic protease","volume":"279","author":"Liz","year":"2004","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B15","doi-asserted-by":"crossref","first-page":"D227","DOI":"10.1093\/nar\/gkp971","article-title":"MEROPS: the peptidase database","volume":"38","author":"Rawlings","year":"2010","journal-title":"Nucleic Acids Res."},{"key":"2021112217284830000_B16","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1042\/BJ20082090","article-title":"Substrate specificity of transthyretin: identification of natural substrates in the nervous system","volume":"419","author":"Liz","year":"2009","journal-title":"Biochem. J."},{"key":"2021112217284830000_B17","doi-asserted-by":"crossref","first-page":"e2899","DOI":"10.1371\/journal.pone.0002899","article-title":"Transthyretin protects against A-\u03b2 peptide toxicity by proteolytic cleavage of the peptide: a mechanism sensitive to the Kunitz protease inhibitor","volume":"3","author":"Costa","year":"2008","journal-title":"PLoS ONE"},{"key":"2021112217284830000_B18","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/S0022-2275(20)39898-9","article-title":"Molecular physiology of reverse cholesterol transport","volume":"36","author":"Fielding","year":"1995","journal-title":"J. Lipid Res."},{"key":"2021112217284830000_B19","doi-asserted-by":"crossref","first-page":"10351","DOI":"10.1021\/bi060726t","article-title":"Contributions of the N- and C-terminal helical segments to the lipid-free structure and lipid interaction of apolipoprotein A-I","volume":"45","author":"Tanaka","year":"2006","journal-title":"Biochemistry"},{"key":"2021112217284830000_B20","doi-asserted-by":"crossref","first-page":"2385","DOI":"10.1194\/jlr.M700158-JLR200","article-title":"ApoA-I cleaved by transthyretin has reduced ability to promote cholesterol efflux and increased amyloidogenicity","volume":"48","author":"Liz","year":"2007","journal-title":"J. Lipid Res."},{"key":"2021112217284830000_B21","doi-asserted-by":"crossref","first-page":"5346","DOI":"10.1021\/bi961649c","article-title":"Characterization of two highly amyloidogenic mutants of transthyretin","volume":"36","author":"Goldsteins","year":"1997","journal-title":"Biochemistry"},{"key":"2021112217284830000_B22","doi-asserted-by":"crossref","first-page":"3116","DOI":"10.1074\/jbc.M510096200","article-title":"Substrate specificity of human kallikrein 6: salt and glycosaminoglycan activation effects","volume":"281","author":"Angelo","year":"2006","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B23","doi-asserted-by":"crossref","first-page":"7114","DOI":"10.1021\/bi952701s","article-title":"Characterization of the P2\u2032 and P3\u2032 specificities of thrombin using fluorescence-quenched substrates and mapping of the subsites by mutagenesis","volume":"35","author":"Le Bonniec","year":"1996","journal-title":"Biochemistry"},{"key":"2021112217284830000_B24","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1016\/S0076-6879(81)80043-2","article-title":"Cathepsin B, Cathepsin H, and cathepsin L","volume":"80","author":"Barrett","year":"1981","journal-title":"Methods Enzymol."},{"key":"2021112217284830000_B25","doi-asserted-by":"crossref","first-page":"3112","DOI":"10.1021\/es049932j","article-title":"Influence of the sea rush Juncus maritimus on metal concentration and speciation in estuarine sediment colonized by the plant","volume":"38","author":"Almeida","year":"2004","journal-title":"Environ. Sci. Technol."},{"key":"2021112217284830000_B26","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.ejmech.2004.10.013","article-title":"Synthesis and evaluation of new tripeptide phosphonate inhibitors of MMP-8 and MMP-2","volume":"40","author":"Agamennone","year":"2005","journal-title":"Eur. J. Med. Chem."},{"key":"2021112217284830000_B27","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1042\/bj1950041","article-title":"Zinc metalloenzyme properties of active and latent collagenase from rabbit bone","volume":"195","author":"Swann","year":"1981","journal-title":"Biochem. J."},{"key":"2021112217284830000_B28","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1021\/bi00908a006","article-title":"The mechanism of inhibition of carboxypeptidase A by 1,10-phenanthroline","volume":"1","author":"Felber","year":"1962","journal-title":"Biochemistry"},{"key":"2021112217284830000_B29","first-page":"105","article-title":"Inhibition of proteolytic enzymes","volume-title":"Proteolytic Enzymes: a Practical Approach","author":"Salvesen","year":"1989"},{"key":"2021112217284830000_B30","doi-asserted-by":"crossref","first-page":"4601","DOI":"10.1016\/S0021-9258(19)42460-5","article-title":"Metal substitutions and inhibition of thermolysin: spectra of the cobalt enzyme","volume":"249","author":"Holmquist","year":"1974","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B31","doi-asserted-by":"crossref","first-page":"13910","DOI":"10.1021\/bi971155v","article-title":"Purification, characterization, and inhibition of peptide deformylase from Escherichia coli","volume":"36","author":"Rajagopalan","year":"1997","journal-title":"Biochemistry"},{"key":"2021112217284830000_B32","doi-asserted-by":"crossref","first-page":"31731","DOI":"10.1074\/jbc.M110.157206","article-title":"Novel Zn2+-binding sites in human transthyretin: implications for amyloidogenesis and retinol-binding protein recognition","volume":"285","author":"Palmieri","year":"2010","journal-title":"J. Biol. Chem."},{"key":"2021112217284830000_B33","doi-asserted-by":"crossref","first-page":"1955","DOI":"10.1002\/pro.5560041001","article-title":"Structural analysis of zinc substitutions in the active site of thermolysin","volume":"4","author":"Holland","year":"1995","journal-title":"Protein Sci."},{"key":"2021112217284830000_B34","doi-asserted-by":"crossref","first-page":"13938","DOI":"10.1021\/bi9712495","article-title":"Evidence by site-directed mutagenesis that arginine 203 of thermolysin and arginine 717 of neprilysin (neutral endopeptidase) play equivalent critical roles in substrate hydrolysis and inhibitor binding","volume":"36","author":"Marie-Claire","year":"1997","journal-title":"Biochemistry"},{"key":"2021112217284830000_B35","doi-asserted-by":"crossref","first-page":"11442","DOI":"10.1021\/bi011194d","article-title":"An engineered transthyretin monomer that is nonamyloidogenic, unless it is partially denatured","volume":"40","author":"Jiang","year":"2001","journal-title":"Biochemistry"},{"key":"2021112217284830000_B36","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1002\/jmr.1112","article-title":"Structure and assembly\u2013disassembly properties of wild-type transthyretin amyloid protofibrils observed with atomic force microscopy","volume":"24","author":"Pires","year":"2010","journal-title":"J. Mol. Recognit."},{"key":"2021112217284830000_B37","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1016\/B978-0-12-079611-3.50304-9","article-title":"O-Sialoglycoprotein endopeptidase","volume-title":"Handbook of Proteolytic Enzymes","author":"Jiang","year":"2004","edition":"2nd edn"},{"key":"2021112217284830000_B38","doi-asserted-by":"crossref","first-page":"D211","DOI":"10.1093\/nar\/gkp985","article-title":"The Pfam protein families database","volume":"38","author":"Finn","year":"2010","journal-title":"Nucleic Acids Res."},{"key":"2021112217284830000_B39","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1201\/9780203910450.ch79","article-title":"Thermolysin","volume-title":"Handbook of Food Enzymology","author":"Inouye","year":"2002"},{"key":"2021112217284830000_B40","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1042\/BJ20040634","article-title":"Evaluation of angiotensin-converting enzyme (ACE), its homologue ACE2 and neprilysin in angiotensin peptide metabolism","volume":"383","author":"Rice","year":"2004","journal-title":"Biochem. J."},{"key":"2021112217284830000_B41","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1515\/BC.2007.048","article-title":"Neprilysin carboxydipeptidase specificity studies and improvement in its detection with fluorescence energy transfer peptides","volume":"388","author":"Barros","year":"2007","journal-title":"Biol. Chem."},{"key":"2021112217284830000_B42","volume-title":"Henry's Clinical Diagnosis and Management by Laboratory Methods","author":"McPherson","year":"2007","edition":"21st edn"}],"container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/443\/3\/769\/671839\/bj4430769.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/443\/3\/769\/671839\/bj4430769.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T01:20:25Z","timestamp":1637630425000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/443\/3\/769\/80470\/Transthyretin-is-a-metallopeptidase-with-an"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,4,16]]},"references-count":42,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2012,5,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj20111690","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,4,16]]}}}