tailieunhanh - Báo cáo khoa học: Identification of novel carbohydrate modifications on Campylobacter jejuni 11168 flagellin using metabolomics-based approaches

ACTH-stimulated aldosterone secretion can be inhibited by atrio-natri-uretic peptide⁄cGMP. The mechanism behind this modulation has been reported to involve cGMP-dependent activation of phosphodiesterase 2 (PDE2) and hydrolysis of cAMP. Recently it was reported that activation of cGMP-dependent protein kinase II (cGKII) stimulated aldosterone secretion in rat zona glomerulosa cells. | Identification of novel carbohydrate modifications on Campylobacter jejuni 11168 flagellin using metabolomics-based approaches Susan M. Logan1 Joseph P. M. Hui2 Evgeny Vinogradov1 Annie J. Aubry1 Jeremy E. Melanson2 John F. Kelly1 Harald Nothaft1 and Evelyn C. Soo2 1 NRC-Institute for BiologicalSciences Ottawa Canada 2 NRC-Institute for Marine Biosciences Halifax Canada Keywords Campylobacter flagellin glycosylation metabolomics pseudaminic acid Correspondence E. C. Soo MS Metabolomics Group NRC-Institute for Marine Biosciences 1411 Oxford Street Halifax NS B3H 3Z1 Canada Fax 1 902 426 9413 Tel 1 902 426 0780 E-mail Received 22 September 2008 revised 3 December 2008 accepted 5 December 2008 doi It is well known that the flagellin of Campylobacter jejuni is extensively glycosylated by pseudaminic acid and the related acetamindino derivative in addition to flagellin glycosylation being essential for motility and colonization of host cells. Recently the use of metabolomics permitted the unequivocal characterization of unique flagellin modifications in Campylobacter including novel legionaminic acid sugars in Campylobacter coli which had been impossible to ascertain in earlier studies using proteomics-based approaches. To date the precise identities of the flagellin glycosylation modifications have only been elucidated for C. jejuni 81-176 and C. coli VC167 and those present in the first genome-sequenced strain C. jejuni 11168 remain elusive due to lability and respective levels of individual gly-can modifications. We report the characterization of the carbohydrate modifications on C. jejuni 11168 flagellin using metabolomics-based approaches. Detected as their corresponding CMP-linked precursors structural information on the flagellin modifications was obtained using a combination of MS and NMR spectroscopy. In addition to the pseudaminic acid and legionaminic acid sugars known to be present on Campylobacter .