title: One-pot synthesis of high molecular weight synthetic heteroprotein dimers driven by charge complementarity electrostatic interactions.
abstract: Despite the importance of protein dimers and dimerization in biology, the formation of protein dimers through synthetic covalent chemistry has not found widespread use. In the case of maleimide-cysteine-based dimerization of proteins, we show here that when the proteins have the same charge, dimerization appears to be inherently difficult with yields around 1% or less, regardless of the nature of the spacer used or whether homo- or heteroprotein dimers are targeted. In contrast, if the proteins have opposing (complementary) charges, the formation of heteroprotein dimers proceeds much more readily, and in the case of one high molecular weight (>80 kDa) synthetic dimer between cytochrome c and bovine serum albumin, a 30% yield of the purified, isolated dimer was achieved. This represents at least a 30-fold increase in yield for protein dimers formed from proteins with complementary charges, compared to when the proteins have the same charge, under otherwise similar conditions. These results illustrate the role of ionic supramolecular interactions in controlling the reactivity of proteins toward bis-functionalized spacers. The strategy here for effective synthetic dimerization of proteins could be very useful for developing novel approaches to study the important role of protein-protein interactions in chemical biology.
authors.affiliation: School of Chemistry, The Australian Centre for Nanomedicine and the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and ‡School of Biotechnology and Biomolecular Sciences, The University of New South Wales , Sydney, NSW 2052, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Hvasanov
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Nam
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Peterson
authors.forename: Dithepon
authors.initials: D
authors.lastname: Pornsaksit
authors.forename: Jörg
authors.initials: J
authors.lastname: Wiedenmann
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Marquis
authors.forename: Pall
authors.initials: P
authors.lastname: Thordarson
mesh_terms: D000818:Animals; D001669:Biochemical Phenomena; D002417:Cattle; D003545:Cysteine / Q000737:chemistry; D045304:Cytochromes c / Q000138:chemical synthesis* / Q000737:chemistry; D019281:Dimerization; D008958:Models, Molecular; D008970:Molecular Weight; D055503:Protein Multimerization; D011506:Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D012709:Serum Albumin / Q000138:chemical synthesis* / Q000737:chemistry; D055672:Static Electricity
chemical_list: D011506:Proteins; D012709:Serum Albumin; D045304:Cytochromes c; D003545:Cysteine