title: A supramolecular complex between proteinases and beta-cyclodextrin that preserves enzymatic activity: physicochemical characterization.
abstract: BACKGROUND
  Cyclodextrins are suitable drug delivery systems because of their ability to subtly modify the physical, chemical, and biological properties of guest molecules through labile interactions by formation of inclusion and/or association complexes. Plant cysteine proteinases from Caricaceae and Bromeliaceae are the subject of therapeutic interest, because of their anti-inflammatory, antitumoral, immunogenic, and wound-healing properties.
  
  
  METHODS
  In this study, we analyzed the association between beta-cyclodextrin (betaCD) and fraction P1G10 containing the bioactive proteinases from Carica candamarcensis, and described the physicochemical nature of the solid-state self-assembled complexes by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and nuclear magnetic resonance (NMR), as well as in solution by circular dichroism (CD), isothermal titration calorimetry (ITC), and amidase activity.
  
  
  CONCLUSIONS
  The physicochemical analyses suggest the formation of a complex between P1G10 and betaCD. Higher secondary interactions, namely hydrophobic interactions, hydrogen bonding and van der Waals forces were observed at higher P1G10 : betaCD mass ratios. These results provide evidence of the occurrence of strong solid-state supramolecular non-covalent interactions between P1G10 and betaCD. Microcalorimetric analysis demonstrates that complexation results in a favorable enthalpic contribution, as has already been described during formation of similar betaCD inclusion compounds. The amidase activity of the complex shows that the enzyme activity is not readily available at 24 hours after dissolution of the complex in aqueous buffer; the proteinase becomes biologically active by the second day and remains stable until day 16, when a gradual decrease occurs, with basal activity attained by day 29.
  
  
  CONCLUSIONS
  The reported results underscore the potential for betaCDs as candidates for complexing cysteine proteinases, resulting in supramolecular arrays with sustained proteolytic activity.
authors.affiliation: Department of Chemistry, Institute of Exact Sciences, Universidade Federal de Minas Gerais (UFMG), Antonio Carlos 6627, Belo Horizonte 31270-901, Brazil.
authors.forename: Angelo M L
authors.initials: AM
authors.lastname: Denadai
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Santoro
authors.forename: Miriam T P
authors.initials: MT
authors.lastname: Lopes
authors.forename: Angélica
authors.initials: A
authors.lastname: Chenna
authors.forename: Frederico B
authors.initials: FB
authors.lastname: de Sousa
authors.forename: Gabriela M
authors.initials: GM
authors.lastname: Avelar
authors.forename: Marco R Túlio
authors.initials: MR
authors.lastname: Gomes
authors.forename: Fanny
authors.initials: F
authors.lastname: Guzman
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Salas
authors.forename: Rubén D
authors.initials: RD
authors.lastname: Sinisterra
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism; D002151:Calorimetry / Q000379:methods; D002152:Calorimetry, Differential Scanning; D029441:Carica / Q000737:chemistry*; D002942:Circular Dichroism; D007840:Latex / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010447:Peptide Hydrolases / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014961:X-Ray Diffraction; D047392:beta-Cyclodextrins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D007840:Latex; D047392:beta-Cyclodextrins; D010447:Peptide Hydrolases; D000581:Amidohydrolases; C019665:amidase