title: Evaluation of multivalent dendrimers based on melamine: kinetics of thiol-disulfide exchange depends on the structure of the dendrimer.
abstract: The rate of thiol-disulfide exchange of dansyl groups mediated by dithiothreitol depends on the structure of the dendrimer. In general, the rate of exchange decreases as the size of the dendrimer increases. Dendrimers with disulfides attached near the core undergo exchange more slowly than dendrimers with disulfides near the periphery. Exchange is a bimolecular (noncooperative) process between dansyl-linked disulfides and dithiothreitol. No evidence for intramolecular macrocylization (cooperative) exchange is observed. Mass spectrometry is used to follow exchange in two dendrimers, providing qualitative and quantitative information about this process. Mathematical models suggest that the rates for exchange for all disulfides of a dendrimer are similar, but increase as the exchange reaction progresses.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Shane E
authors.initials: SE
authors.lastname: Tichy
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Pérez
authors.forename: Gheorghe C
authors.initials: GC
authors.lastname: Maria
authors.forename: Paul A
authors.initials: PA
authors.lastname: Lindahl
authors.forename: Eric E
authors.initials: EE
authors.lastname: Simanek
mesh_terms: D003198:Computer Simulation; D004220:Disulfides / Q000737:chemistry*; D004229:Dithiothreitol / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D007700:Kinetics; D013058:Mass Spectrometry; D008958:Models, Molecular; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*
chemical_list: D004220:Disulfides; D011108:Polymers; D013438:Sulfhydryl Compounds; D014227:Triazines; D005978:Glutathione; C011907:melamine; D004229:Dithiothreitol