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Eade CR, Wallen TW, Gates CE, Oliverio CL, Scarbrough BA, Reid AJ, Jorgenson MA, Young KD, Troutman JM. Making the Enterobacterial Common Antigen Glycan and Measuring Its Substrate Sequestration. ACS Chem Biol 2021; 16:691-700. [PMID: 33740380 DOI: 10.1021/acschembio.0c00983] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The enterobacterial common antigen (ECA), a three-sugar repeat unit polysaccharide produced by Enterobacteriaceae family members, impacts bacterial outer membrane permeability, and its biosynthesis affects the glycan landscape of the organism. ECA synthesis impacts the production of other polysaccharides by reducing the availability of shared substrates, the most notable of which is the 55-carbon polyisoprenoid bactoprenyl phosphate (BP), which serves as a carrier for the production of numerous bacterial glycans including ECA, peptidoglycan, O-antigen, and more. Here, using a combination of in vitro enzymatic synthesis and liquid chromatography-mass spectrometry (LC-MS) analysis of bacterial lysates, we provide biochemical evidence for the effect on endogenous polyisoprenoid pools from cell culture that arises from glycan pathway disruption. In this work, we have cloned and expressed each gene involved in ECA repeat unit biosynthesis and reconstituted the pathway in vitro, providing LC-MS characterized standards for the investigation of cellular glycan-linked intermediates and BP. We then generated ECA deficient mutants in genes associated with production of the polysaccharide, which we suspected would accumulate materials identical to our standards. We found that indeed accumulated products from these cells were indistinguishable from our enzymatically prepared standards, and moreover we observed a concomitant decrease in cellular BP levels with each mutant. This work provides the first direct biochemical evidence for the sequestration of BP upon the genetic disruption of glycan biosynthesis pathways in bacteria. This work also provides methods for the direct assessment of both the ECA glycan, and a new understanding of the dynamic interdependence of the bacterial polysaccharide repertoire.
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Affiliation(s)
- Colleen R. Eade
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Timothy W. Wallen
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Claire E. Gates
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
- Biological and Biomedical Sciences Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Cassidy L. Oliverio
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Beth A. Scarbrough
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Amanda J. Reid
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Matthew A. Jorgenson
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, United States
| | - Kevin D. Young
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, United States
| | - Jerry M. Troutman
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
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Greene LK, Wallen TW, Moresco A, Goodwin TE, Drea CM. Reproductive endocrine patterns and volatile urinary compounds of Arctictis binturong: discovering why bearcats smell like popcorn. Naturwissenschaften 2016; 103:37. [PMID: 27056047 DOI: 10.1007/s00114-016-1361-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 03/22/2016] [Accepted: 03/27/2016] [Indexed: 12/21/2022]
Abstract
Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viverrid--the binturong (Arctictis binturong). Female binturongs are larger than and dominate males, and both sexes engage in glandular and urinary scent marking. Using a large (n = 33), captive population, we collected serum samples to measure circulating sex steroids via enzyme immunoassay and urine samples to assay volatile chemicals via gas chromatography-mass spectrometry. Male binturongs had expectedly greater androgen concentrations than did females but, more unusually, had equal estrogen concentrations, which may be linked to male deference. Males also expressed a significantly richer array of volatile chemical compounds than did females. A subset of these volatile chemicals resisted decay at ambient temperatures, potentially indicating their importance as long-lasting semiochemicals. Among these compounds was 2-acetyl-1-pyrroline (2-AP), which is typically produced at high temperatures by the Maillard reaction and is likely to be responsible for the binturong's characteristic popcorn aroma. 2-AP, the only compound expressed by all of the subjects, was found in greater abundance in males than females and was significantly and positively related to circulating androstenedione concentrations in both sexes. This unusual compound may have a more significant role in mammalian semiochemistry than previously appreciated. Based on these novel data, we suggest that hormonal action and potentially complex chemical reactions mediate communication of the binturong's signature scent and convey information about sex and reproductive state.
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Affiliation(s)
- Lydia K Greene
- University Program in Ecology, Duke University, Durham, NC, USA
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Timothy W Wallen
- Department of Chemistry, Hendrix College, Conway, AR, USA
- National Center for Environmental Health, Division of Laboratory Sciences, Clinical Chemistry Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Anneke Moresco
- Carnivore Preservation Trust (now Carolina Tiger Rescue), 1940 Hanks Chapel Road, Pittsboro, North Carolina, 27312, USA
- Denver Zoo, 2300 Steele Street, Denver, Colorado, 80205, USA
| | | | - Christine M Drea
- University Program in Ecology, Duke University, Durham, NC, USA.
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
- Department of Biology, Duke University, Durham, NC, USA.
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