| Title: | Towards structural determination of the ComX pheromone: synthetic studies on peptides containing geranyltryptophan |
| Author(s): | Okada M; Sato I; Cho SJ; Suzuki Y; Ojika M; Dubnau D; Sakagami Y; |
| Address: | "Graduate School of Bioagricultural Sciences, Nagoya University, Japan" |
| Journal Title: | Biosci Biotechnol Biochem |
| ISSN/ISBN: | 0916-8451 (Print) 0916-8451 (Linking) |
| Abstract: | "Bacteria produce and respond to signal molecules depending on their cell density. This process is called 'quorum sensing'. The ComX pheromone, controlled by quorum sensing, activates natural genetic competence in Bacillus subtilis. ComX is an oligopeptide with a posttranslational modification. It has been suggested that ComX pheromone is modified with an isoprenoid at its tryptophan residue, but the complete chemical structure is unknown. We first determined the molecular formula of ComX(RO-E-2), a competence factor for B. subtilis strain RO-E-2. Then we synthesized putative pheromones with 1-, 2-, 4-, 5-, 6-, or 7-geranyl substituted tryptophan residues. The regio- and stereo-selective synthesis of the geranyl tryptophans was successful, and we prepared the six peptides with modified tryptophan residues. These peptides had the same molecular formula and showed similar hydrophobicity to the natural ComX(RO-E-2) in LC-MS analysis. But, none of them showed the same retention time as the natural pheromone and none exhibited its biological activity. These results suggest that the isoprenoid modification pattern of the tryptophan residue is more complex than postulated" |
| Keywords: | "Bacillus subtilis/metabolism Bacterial Proteins/chemical synthesis/*chemistry/genetics Chromatography, High Pressure Liquid Chromatography, Liquid Escherichia coli/metabolism Indicators and Reagents Magnetic Resonance Spectroscopy Peptides/*chemical synth;" |
| Notes: | "MedlineOkada, Masahiro Sato, Isao Cho, Soo Jeong Suzuki, Yoshihiro Ojika, Makoto Dubnau, David Sakagami, Youji eng GM57720/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. England 2004/11/27 Biosci Biotechnol Biochem. 2004 Nov; 68(11):2374-87. doi: 10.1271/bbb.68.2374" |
