title: Catalytic Formation of Disulfide Bonds in Peptides by Molecularly Imprinted Microgels at Oil/Water Interfaces.
abstract: This work describes the preparation and investigation of molecularly imprinted polymer (MIP) microgel (MG) stabilized Pickering emulsions (PEs) for their ability to catalyze the formation of disulfide bonds in peptides at the O/W interface. The MIP MGs were synthesized via precipitation polymerization and a programmed initiator change strategy. The MIP MGs were characterized using DLS analysis, SEM measurement, and optical microscopy analysis. The dry and wet MIP MGs showed a hydrodynamic diameter of 100 and 280 nm, respectively. A template rebinding experiment showed that the MIP MGs bound over two times more template (24 mg g-1) compared to the uptake displayed by a nonimprinted reference polymer (NIP) MG (10 mg g-1) at saturation. Using the MIP MGs as stabilizers, catalytic oxidation systems were prepared by emulsifying the oil phase and water phase in the presence of different oxidizing agents. During the cyclization, the isolation of the thiol precursors and the oxidizing reagents nonselectively decreased the formation of the byproducts, while the imprinted cavities on the MIP MGs selectively promoted the intramolecular cyclization of peptides. When I2was used as the oxidizing agent, the MIP-PE-I2system showed a product yield of 50%, corresponding to a nearly 2-fold increase compared to that of the nonimprinted polymer NIP-PE-I2system (26%). We believe the interfacial catalysis system presented in this work may offer significant benefits in synthetic peptide chemistry by raising productivity while suppressing the formation of byproducts.
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology , Hangkong Road #13, Wuhan, Hubei 430030, China.|Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden.|G&T Septech AS , P.O. Box 33, 1917 Ytre Enebakk, Norway.
authors.forename: Xiantao
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden.|School of Pharmacy, University of Oslo , P.O. Box 1068, 0316 Blindern Oslo, Norway.|G&T Septech AS , P.O. Box 33, 1917 Ytre Enebakk, Norway.
authors.forename: Chuixiu
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden.
authors.forename: Sudhirkumar
authors.initials: S
authors.lastname: Shinde
authors.affiliation: Department of Biomedical Engineering, Lund University , 221 00 Lund, Sweden.
authors.forename: Kishore Kumar
authors.initials: KK
authors.lastname: Jagadeesan
authors.affiliation: Department of Biomedical Engineering, Lund University , 221 00 Lund, Sweden.
authors.forename: Simon
authors.initials: S
authors.lastname: Ekström
authors.affiliation: INFU, Technische Universität Dortmund , 44221 Dortmund, Germany.
authors.forename: Emelie
authors.initials: E
authors.lastname: Fritz
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University , SE20506 Malmö, Sweden.
authors.forename: Börje
authors.initials: B
authors.lastname: Sellergren
keywords: Pickering emulsions; disulfide-rich cyclic peptides; interfacial catalysis; intramolecular cyclization; molecularly imprinted polymers