1. Photoactivatable peptides based on BMS-197525: a potent antagonist of the human thrombin receptor (PAR-1)
J T Elliott, W J Hoekstra, B E Maryanoff, G D Prestwich Bioorg Med Chem Lett. 1999 Jan 18;9(2):279-84. doi: 10.1016/s0960-894x(98)00730-6.
Photoactivatable analogs of the human thrombin receptor (PAR-1) antagonist, N-trans-cinnamoyl-p-fluoroPhe-p-guanidinoPhe-Leu-Arg-NH2 (BMS-197525), were prepared with benzophenone substitutions in the N-terminal, Leu, or Arg position. The analogs retained antagonist activity (with reduced potency); the tritium-labeled isotopomers are potential photoaffinity labels for the receptor. C-Terminal extension of the analogs with ornithine(biotin) did not significantly alter antagonist potency.
2. Identification of novel peptides specifically binding to endometriosis by screening phage-displaying peptide libraries
Chi-Chen Chang, Yao-Yuan Hsieh, Yu-Kuo Wang, Kung-Hao Hsu, Horng-Der Tsai, Fuu-Jen Tsai, Chih-Sheng Lin Fertil Steril. 2009 Dec;92(6):1850-5. doi: 10.1016/j.fertnstert.2008.09.007. Epub 2009 Feb 6.
Objective: To search for novel peptides and common binding motif that specifically bind to endometriosis. Design: Prospective study. Setting: Department of Biological Science and Technology in national university. Patient(s): Specimens were divided into [1] ectopic endometrium (n = 10); [2] eutopic endometrium (n = 10). Intervention(s): Peptides specifically binding to endometriosis are screened from a phage-displaying peptide library (Ph.D.-12) by using whole-cell screening technique after an adsorption elution amplification procedure. Main outcome measure(s): Combinatorial peptide libraries were used to identify small molecules that bind with high affinity to receptor molecules and mimic the interaction with natural ligands. Few pans of positive phage clones with significantly positive signals were identified by ELISA and analyzed by DNA sequencing. Result(s): During the biopanning processes, the recovered phage number (10(6) pfu/mL) in parts 1, 2, 3, 4, and 5 of the study were 9, 33, 82, 142, and 169. Nine phages consistently had residue Arg, whereas six clones had a consensus motif of Arg-X-Arg-X-X-X-X-Arg. The biotin-labeled peptide bound to endometriosis cells in a dose-dependent manner, yet the control peptide revealed lesser binding activity. Conclusion(s): The novel motif is associated with higher affinity of endometriosis, which might be useful in endometriosis targeting and as potential antiendometriosis therapies. We provide one potential approach for novel therapies toward endometriosis.
3. Intragranular colocalization of arginine vasopressin and methionine-enkephalin-octapeptide in CRF-axons in the rat median eminence
S Hisano, Y Tsuruo, S Katoh, S Daikoku, N Yanaihara, T Shibasaki Cell Tissue Res. 1987 Sep;249(3):497-507. doi: 10.1007/BF00217321.
Ultrastructural appearances of axonal terminals containing corticoliberin (CRF) were examined in the rat median eminence prepared by a freeze-drying procedure. Immunolabeling was performed by using 5-, 8-, or 15-nm gold-antibody complexes for CRF, arginine vasopressin (VP) and methionine-enkephalin-octapeptide (Enk-8), singly or in combination. In intact animals, the CRF-containing secretory granules were only slightly labeled with gold-anti-VP or -Enk-8. In adrenalectomized rats, granules within single axons appeared to be labeled with all the immunogold complexes. This intragranular colocalization of the three antigens was confirmed by using three neighboring sections of the same axon terminals which were stained separately with each one of the antibodies and visualized with the avidin-biotin-peroxidase complex method. The granules labeled for CRF had decreased 9 days after adrenalectomy but had increased again by day 21, while those labeled for VP steadily increased after adrenalectomy. However, this did not correspond with the appearances of cell bodies in the paraventricular nucleus; the cell bodies labeled for both CRF and VP steadily increased in number and in stainability. By contrast, Enk-8 immunoreactivity in the axonal terminals and cell bodies was not affected by adrenalectomy. These findings suggest that although the three peptides could be released simultaneously from the axonal terminals, VP may play some special role in the expression of CRF activity.