title: Absence of sodA Increases the Levels of Oxidation of Key Metabolic Determinants of Borrelia burgdorferi.
abstract: Borrelia burgdorferi, the causative agent of Lyme disease, alters its gene expression in response to environmental signals unique to its tick vector or vertebrate hosts. B. burgdorferi carries one superoxide dismutase gene (sodA) capable of controlling intracellular superoxide levels. Previously, sodA was shown to be essential for infection of B. burgdorferi in the C3H/HeN model of Lyme disease. We employed two-dimensional electrophoresis (2-DE) and immunoblot analysis with antibodies specific to carbonylated proteins to identify targets that were differentially oxidized in the soluble fractions of the sodA mutant compared to its isogenic parental control strain following treatment with an endogenous superoxide generator, methyl viologen (MV, paraquat). HPLC-ESI-MS/MS analysis of oxidized proteins revealed that several proteins of the glycolytic pathway (BB0057, BB0020, BB0348) exhibited increased carbonylation in the sodA mutant treated with MV. Levels of ATP and NAD/NADH were reduced in the sodA mutant compared with the parental strain following treatment with MV and could be attributed to increased levels of oxidation of proteins of the glycolytic pathway. In addition, a chaperone, HtpG (BB0560), and outer surface protein A (OspA, BBA15) were also observed to be oxidized in the sodA mutant. Immunoblot analysis revealed reduced levels of Outer surface protein C (OspC), Decorin binding protein A (DbpA), fibronectin binding protein (BBK32), RpoS and BosR in the sodA mutant compared to the control strains. Viable sodA mutant spirochetes could not be recovered from both gp91/phox-⁄- and iNOS deficient mice while borrelial DNA was detected in multiple tissues samples from infected mice at significantly lower levels compared to the parental strain. Taken together, these observations indicate that the increased oxidation of select borrelial determinants and reduced levels of critical pathogenesis-associated lipoproteins contribute to the in vivo deficit of the sodA mutant in the mouse model of Lyme disease. This study, utilizing the sodA mutant, has provided insights into adaptive capabilities critical for survival of B. burgdorferi in its hosts.
authors: South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America; Department of Biology, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America.
authors: Maria D
authors: MD
authors: Esteve-Gassent
authors: South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America; Center of Excellence in Infection Genomics, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America.
authors: Trever C
authors: TC
authors: Smith
authors: Department of Biology, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America.
authors: Christina M
authors: CM
authors: Small
authors: South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America; Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX-77843, United States of America.
authors: Derek P
authors: DP
authors: Thomas
authors: South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America; Center of Excellence in Infection Genomics, The University of Texas at San Antonio, San Antonio, TX-78249, United States of America.
authors: J
authors: J
authors: Seshu
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism; D000954:Antigens, Surface / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000378:metabolism; D025065:Borrelia burgdorferi / Q000235:genetics* / Q000472:pathogenicity*; D002851:Chromatography, High Pressure Liquid; D006019:Glycolysis / Q000502:physiology; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D008074:Lipoproteins / Q000378:metabolism; D008193:Lyme Disease / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009243:NAD / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D010084:Oxidation-Reduction; D010269:Paraquat / Q000494:pharmacology; D011971:Receptors, Immunologic / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics*; D053719:Tandem Mass Spectrometry
chemical_list: D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; C112557:DdpB protein, Borrelia burgdorferi; D018841:HSP90 Heat-Shock Proteins; D008074:Lipoproteins; C072045:OspA protein; C079616:OspC protein; C105949:Pirb protein, mouse; D011971:Receptors, Immunologic; C106209:p35 antigen, Borrelia; D009243:NAD; C066720:HtpG protein, bacteria; D000255:Adenosine Triphosphate; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C095500:SodA protein, Bacteria; D013482:Superoxide Dismutase; D010269:Paraquat