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Towards a new approach to phenylketonuria treatment : stabilization of pheylalanine hydroxylase using nanobiomaterials

dc.contributor.advisorAlmeida, António José Leitão das Neves, 1963-
dc.contributor.advisorLeandro, Ana Paula Costa dos Santos Peralta, 1961-
dc.contributor.advisorBlanco-Prieto, Maria José
dc.contributor.authorLino, Paulo Jorge Ferreira Rama Roque, 1984-
dc.date.accessioned2015-07-13T17:13:13Z
dc.date.available2015-07-13T17:13:13Z
dc.date.issued2015
dc.date.submitted2015
dc.descriptionTese de doutoramento, Farmácia (Tecnologia Farmacêutica), Universidade de Lisboa, Faculdade de Farmácia, 2015por
dc.description.abstractPhenylketonuria (PKU; MIM# 261600), the most frequent inherited disorder of amino acid metabolism, is caused by a deficient activity of human phenylalanine hydroxylase (hPAH; EC 1.14.16.1). To prevent the development of a severe neurophysiological retardation a strict dietetic restriction must be implemented as soon as possible, after birth. However being the only universal treatment available to date, it presents a poor long term compliance with a late onset of neurological symptoms. Aiming at an enzymatic replacement therapy, the use of recombinant proteins is still limited due to its physicochemical instability resulting in a high tendency to form soluble aggregates and consequent loss of biological function throughout pharmaceutical production and storage. In previous studies we have shown that low-molecular-weight polyol compounds stabilize the recombinant hPAH protein, preserving its structure and activity. In the present work our goal was to further stabilize hPAH by combining the use of polyols with the stabilization effect conferred by lyophilisation. Three excipients (glucose, trehalose and melibiose) were found to be able to preserve hPAH structure and function upon lyophilisation. The reconstituted samples maintained 100 % enzyme activity and substrate activation even after one year storage at 4 °C. In addition, protein engineering and the use of polymeric nanobiomaterials were also investigated. Site directed mutagenesis was used in order to change the protein’s surface charge or introduce residues less susceptible to oxidation. The C29S variant showed improved functional and structural properties. Considering polymeric nanobiomaterials, chitosan, hyaluronic acid and cyclodextrins were used to prepare nanoparticulate systems. Bridging the knowledge obtained by in silico and experimental data, we were able to establish the critical parameters that impacted the mild formation of chitosan nanoparticles and optimize a suitable hPAH nanoformulation in terms of particle size, encapsulation efficiency and biocompatibility This project contributed to elucidate the stabilization mechanisms of hPAH, a model protein for the study of inborn errors of metabolism and protein misfolding disorders. It may also result in a novel and effective approach to PKU treatment.por
dc.description.provenanceSubmitted by Amelia Janeiro (ajaneiro@reitoria.ul.pt) on 2015-07-10T17:03:20Z No. of bitstreams: 1 ulsd071004_td_Paulo_Lino.pdf: 8447510 bytes, checksum: 27b9ba5c428a9a3101b47d78e7c13901 (MD5)en
dc.description.provenanceMade available in DSpace on 2015-07-13T17:13:13Z (GMT). No. of bitstreams: 1 ulsd071004_td_Paulo_Lino.pdf: 8447510 bytes, checksum: 27b9ba5c428a9a3101b47d78e7c13901 (MD5) Previous issue date: 2015en
dc.description.sponsorshipFundação para a Ciência e a Tecnologia (FCT), projetos PTDC/EBBBIO/101237/2008, PEst-OE/SAU/UI4013/2011por
dc.identifier.tid101305966
dc.identifier.urihttp://hdl.handle.net/10451/18434
dc.language.isoengpor
dc.subjectTeses de doutoramento - 2015por
dc.titleTowards a new approach to phenylketonuria treatment : stabilization of pheylalanine hydroxylase using nanobiomaterialspor
dc.typedoctoral thesis
dspace.entity.typePublication
oaire.awardURIinfo:eu-repo/grantAgreement/FCT/3599-PPCDT/PTDC%2FQUI%2F64023%2F2006/PT
oaire.awardURIinfo:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBD%2F47946%2F2008/PT
oaire.fundingStream3599-PPCDT
oaire.fundingStreamSFRH
project.funder.identifierhttp://doi.org/10.13039/501100001871
project.funder.identifierhttp://doi.org/10.13039/501100001871
project.funder.nameFundação para a Ciência e a Tecnologia
project.funder.nameFundação para a Ciência e a Tecnologia
rcaap.contributor.authoremailrepositorio@reitoria.ulisboa.pt
rcaap.rightsrestrictedAccesspor
rcaap.typedoctoralThesispor
relation.isProjectOfPublication10b1b175-ffc6-4b7d-8934-a887942d4f55
relation.isProjectOfPublicationa4c34041-b5f5-4480-92d3-b46e793c29fa
relation.isProjectOfPublication.latestForDiscovery10b1b175-ffc6-4b7d-8934-a887942d4f55
thesis.degree.levelDoutorpor
thesis.degree.nameDoutoramento em Farmáciapor

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