title: Immobilized OBOC combinatorial bead array to facilitate multiplicative screening.
abstract: One-bead-one-compound (OBOC) combinatorial library screening has been broadly utilized for the last two decades to identify small molecules, peptides or peptidomimetics targeting variable screening probes such as cell surface receptors, bacteria, protein kinases, phosphatases, proteases etc. In previous screening methods, library beads were suspended in solution and screened against one single probe. Only the positive beads were tracked and isolated for additional screens and finally selected for chemical decoding. During this process, the remaining negative beads were not tracked and discarded. Here we report a novel bead immobilization method such that a bead library array can be conveniently prepared and screened in its entirety, sequentially many times with a series of distinct probes. This method not only allows us to increase the screening efficiency but also permits us to determine the binding profile of each and every library bead against a large number of target receptors. As proof of concept, we serially screened a random OBOC disulfide containing cyclic heptapeptide library with three water soluble dyes as model probes: malachite green, bromocresol purple and indigo carmine. This multiplicative screening approach resulted in a rapid determination of the binding profile of each and every bead respective to each of the three dyes. Beads that interacted with malachite green only, bromocresol purple only, or both indigo carmine and bromocresol purple were isolated, and their peptide sequences were determined with microsequencer. Ultimately, the novel OBOC multiplicative screening approach could play a key role in the enhancement of existing on-bead assays such as whole cell binding, bacteria binding, protein binding, posttranslational modifications etc. with increased efficiency, capacity, and specificity.
authors.affiliation: Department of Biochemistry and Molecular Medicine, UC Davis Cancer Center, University of California Davis, 2700 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Wenwu
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Department of Biochemistry and Molecular Medicine, UC Davis Cancer Center, University of California Davis, 2700 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Bononi
authors.affiliation: Physiology & Cell Biology, University of Nevada School of Medicine, Anderson Rm 104E, UNR, 1664 N. Virginia St. Reno, NV 89557.
authors.forename: Jared
authors.initials: J
authors.lastname: Townsend
authors.affiliation: Department of Biochemistry and Molecular Medicine, UC Davis Cancer Center, University of California Davis, 2700 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Yuanpei
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Medicine, UC Davis Cancer Center, University of California Davis, 2700 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Ruiwu
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Biochemistry and Molecular Medicine, UC Davis Cancer Center, University of California Davis, 2700 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Kit S
authors.initials: KS
authors.lastname: Lam
mesh_terms: D004396:Coloring Agents / Q000032:analysis / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques; D057166:High-Throughput Screening Assays / Q000379:methods*; D008863:Microspheres; D015394:Molecular Structure; D054852:Small Molecule Libraries / Q000032:analysis* / Q000737:chemistry*; D013997:Time Factors
chemical_list: D004396:Coloring Agents; D054852:Small Molecule Libraries