title: Interaction between polyamidoamine (PAMAM) dendrimers and bovine insulin.
abstract: OBJECTIVE
  In this study the mechanism of interactions between polyamidoamine (PAMAM) dendrimers and bovine insulin was examined. The insulin is a 51 amino acid peptide-hormone involved in the homeostasis of blood glucose levels. This molecule consists of two chains - A and B - linked by two disulphide bridges. As insulin contains four tyrosine residues it was possible to evaluate dendrimers effect on protein conformation by measuring changes in the fluorescence spectra of insulin after addition of dendrimers or classical quenchers.
  
  
  METHODS
  PAMAM dendrimers are based on ethylenediamine core and branched units which are built from methyl acrylate and ethylenediamine. PAMAM dendrimers with different surface groups (-COOH, -NH2, -OH) were used. Their size is comparable to insulin.
  
  
  RESULTS
  The experiments show that interactions exist between PAMAM dendrimers and insulin. It was found that these interactions depend on a kind of dendrimer surface groups.
  
  
  CONCLUSIONS
  It is very likely that interactions are of electrostatic nature and cause insulin conformational changes.
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland. jolanta.kujawa@umed.lodz.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Owczarek
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
authors.forename: Olga
authors.initials: O
authors.lastname: Nowacka
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Klajnert
authors.affiliation: Department of Medical Rehabilitation, Faculty of Military Medicine, Medical University of Lodz, Lodz, Poland. jolanta.kujawa@umed.lodz.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kujawa
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Bryszewska
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D050091:Dendrimers / Q000737:chemistry* / Q000378:metabolism*; D004347:Drug Interactions; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000378:metabolism; D007328:Insulin / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D050091:Dendrimers; D007004:Hypoglycemic Agents; D007328:Insulin; C104700:PAMAM Starburst; D014443:Tyrosine