title: The influence of PAMAM dendrimers surface groups on their interaction with porcine pepsin.
abstract: In this study the ability of three polyamidoamine (PAMAM) dendrimers with different surface charge (positive, neutral and negative) to interact with a negatively charged protein (porcine pepsin) was examined. It was shown that the dendrimer with a positively charged surface (G4 PAMAM-NH2), as well as the dendrimer with a neutral surface (G4 PAMAM-OH), were able to inhibit enzymatic activity of pepsin. It was also found that these dendrimers act as mixed partially non-competitive pepsin inhibitors. The negatively charged dendrimer (G3.5 PAMAM-COOH) was not able to inhibit the enzymatic activity of pepsin, probably due to the electrostatic repulsion between this dendrimer and the protein. No correlation between changes in enzymatic activity of pepsin and alterations in CD spectrum of the protein was observed. It indicates that the interactions between dendrimers and porcine pepsin are complex, multidirectional and not dependent only on disturbances of the secondary structure.
authors.affiliation: Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-236 Lodz, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Ciolkowski
authors.forename: Monika
authors.initials: M
authors.lastname: Rozanek
authors.forename: Maria
authors.initials: M
authors.lastname: Bryszewska
authors.forename: Barbara
authors.initials: B
authors.lastname: Klajnert
mesh_terms: D000818:Animals; D002942:Circular Dichroism; D050091:Dendrimers / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010434:Pepsin A / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D017433:Protein Structure, Secondary; D055672:Static Electricity; D013552:Swine
chemical_list: D050091:Dendrimers; C104700:PAMAM Starburst; C531249:Poly(amidoamine); D011073:Polyamines; D010434:Pepsin A
keywords: ATP-ase; CD; Circular dichroism; Dendrimer-protein interaction; Enzyme inhibition; G3.5 PAMAM-COOH; G4 PAMAM-NH(2); G4 PAMAM-OH; MRE; PAMAM; PAMAM dendrimers; Porcine pepsin; adenosine triphosphatase; circular dichroism; fourth generation PAMAM dendrimer with amine terminal groups; fourth generation PAMAM dendrimer with hydroxyl terminal groups; mean residue elipticity; polyamidoamine; third and a half generation PAMAM dendrimer with carboxyl terminal groups