Synthesis and screening of a cyclic peptide library: discovery of small-molecule ligands against human prolactin receptor.
Prolactin receptor is involved in normal lactation and reproduction; however, excessive prolactin levels can cause various reproductive disorders such as prolactinomas. Small-molecule antagonists against the human prolactin receptor (hPRLr) thus have potential clinical applications and may serve as useful molecular probes in biomedical research. In this work, we synthesized a large, support-bound cyclic peptide library (theoretical diversity of 1.2x10(7)) on 90-microm TentaGel beads and screened it against the extracellular domain of hPRLr. To facilitate hit identification, each TentaGel bead was spatially segregated into outer and inner layers, with a cyclic peptide displayed on the bead surface while the bead interior contained the corresponding linear peptide. The identity of a positive bead was revealed by sequencing the linear encoding peptide within the bead by partial Edman degradation/mass spectrometry. Screening of the library resulted in 20 hits, two of which were selected for further analysis and shown to bind to hPRLr with dissociation constants of 2-3 microM.
Liu
Tao
T
Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
Joo
Sang Hoon
SH
Voorhees
Jeffrey L
JL
Brooks
Charles L
CL
Pei
Dehua
D
D000595:Amino Acid Sequence; D020650:Combinatorial Chemistry Techniques; D006801:Humans; D008024:Ligands; D008863:Microspheres; D019151:Peptide Library; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D011981:Receptors, Prolactin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020349:Surface Plasmon Resonance
D008024:Ligands; D019151:Peptide Library; D010455:Peptides; D010456:Peptides, Cyclic; D011981:Receptors, Prolactin