scholarly journals Structural mechanisms underlying sequence-dependent variations in GAG affinities of decorin binding protein A, a Borrelia burgdorferi adhesin

2015 ◽  
Vol 467 (3) ◽  
pp. 439-451 ◽  
Author(s):  
Ashli M. Morgan ◽  
Xu Wang
Keyword(s):  
Borrelia Burgdorferi ◽  
Binding Protein ◽  
Protein A ◽  
Binding Pocket ◽  
Sulfated Polysaccharide ◽  
Solution Structures ◽  
C Terminus ◽  
Binding Epitope ◽  
Different Strains ◽  
Structural Mechanisms

Decorin-binding protein A (DBPA) is an important surface adhesin of the bacterium Borrelia burgdorferi, the causative agent of Lyme disease. DBPA facilitates the bacteria's colonization of human tissue by adhering to glycosaminoglycan (GAG), a sulfated polysaccharide. Interestingly, DBPA sequence variation among different strains of Borrelia spirochetes is high, resulting in significant differences in their GAG affinities. However, the structural mechanisms contributing to these differences are unknown. We determined the solution structures of DBPAs from strain N40 of B. burgdorferi and strain PBr of Borrelia garinii, two DBPA variants whose GAG affinities deviate significantly from strain B31, the best characterized version of DBPA. Our structures revealed that significant differences exist between PBr DBPA and B31/N40 DBPAs. In particular, the C-terminus of PBr DBPA, unlike C-termini from B31 and N40 DBPAs, is positioned away from the GAG-binding pocket and the linker between helices one and two of PBr DBPA is highly structured and retracted from the GAG-binding pocket. The repositioning of the C-terminus allowed the formation of an extra GAG-binding epitope in PBr DBPA and the retracted linker gave GAG ligands more access to the GAG-binding epitopes than other DBPAs. Characterization of GAG ligands' interactions with wild-type (WT) PBr and mutants confirmed the importance of the second major GAG-binding epitope and established the fact that the two epitopes are independent of one another and the new epitope is as important to GAG binding as the traditional epitope.

scholarly journals Detection of antibodies to decorin-binding protein A (DbpA) and DbpB after infection of dogs with Borrelia burgdorferi by tick challenge

2020 ◽  
Vol 32 (3) ◽  
pp. 481-485
Author(s):  
Darby G. Oldenburg ◽  
Dean A. Jobe ◽  
Steven D. Lovrich ◽  
Rhonda L. LaFleur ◽  
Douglas W. White ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Ixodes Scapularis ◽  
Binding Protein ◽  
Protein A ◽  
Immune Serum ◽  
Immunoglobulin M ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Serum Samples

We characterized the antibody response to decorin-binding protein A (DbpA) or DbpB from immune serum samples collected from 27 dogs infected with Borrelia burgdorferi by Ixodes scapularis ticks. Immunoglobulin M (IgM) antibodies to DbpA or DbpB were rarely detected, but high levels of IgG antibodies to DbpA were detected in 16 of 27 of the immune sera collected 1 mo after infection, 20 of 25 of the sera collected after 2 mo, and each of the 23, 17, or 11 serum samples evaluated after 3, 4, or 5 mo, respectively. In addition, IgG antibodies to DbpB were detected in 22 of 27 ( p = 0.005) tested dogs after 1 mo, and the frequency of detecting the antibodies thereafter closely mimicked the antibody responses to DbpA. Moreover, antibodies to DbpA or DbpB were not produced by dogs vaccinated with a whole-cell B. burgdorferi bacterin; removing the antibodies to DbpA by adsorption to recombinant DbpA (rDbpA) did not affect the reactivity detected by a rDbpB ELISA. Therefore, the findings from our preliminary study showed that antigenically distinct antibodies to DbpA or DbpB are produced reliably during canine infection with B. burgdorferi, and the response is not confounded by vaccination with a Lyme disease bacterin. Larger studies are warranted to more critically evaluate whether detecting the antibody responses can improve serodiagnostic confirmation of canine Lyme disease.

scholarly journals Complex formation between p53 and replication protein A inhibits the sequence-specific DNA binding of p53 and is regulated by single-stranded DNA.

1997 ◽  
Vol 17 (4) ◽  
pp. 2194-2201 ◽  
Author(s):  
S D Miller ◽  
K Moses ◽  
L Jayaraman ◽  
C Prives
Keyword(s):  
Dna Binding ◽  
Complex Formation ◽  
Binding Protein ◽  
Protein A ◽  
Replication Protein A ◽  
Dna Binding Protein ◽  
Replication Protein ◽  
Single Stranded Dna ◽  
C Terminus ◽  
P53 Response

Human replication protein A (RP-A) (also known as human single-stranded DNA binding protein, or HSSB) is a multisubunit complex involved in both DNA replication and repair. Potentially important to both these functions, it is also capable of complex formation with the tumor suppressor protein p53. Here we show that although p53 is unable to prevent RP-A from associating with a range of single-stranded DNAs in solution, RP-A is able to strongly inhibit p53 from functioning as a sequence-specific DNA binding protein when the two proteins are complexed. This inhibition, in turn, can be regulated by the presence of various lengths of single-stranded DNAs, as RP-A, when bound to these single-stranded DNAs, is unable to interact with p53. Interestingly, the lengths of single-stranded DNA capable of relieving complex formation between the two proteins represent forms that might be introduced through repair and replicative events. Increasing p53 concentrations can also overcome the inhibition by steady-state levels of RP-A, potentially mimicking cellular points of balance. Finally, it has been shown previously that p53 can itself be stimulated for site-specific DNA binding when complexed through the C terminus with short single strands of DNA, and here we show that p53 stays bound to these short strands even after binding a physiologically relevant site. These results identify a potential dual role for single-stranded DNA in the regulation of DNA binding by p53 and give insights into the p53 response to DNA damage.

scholarly journals Evidence for Vaccine Synergy between Borrelia burgdorferi Decorin Binding Protein A and Outer Surface Protein A in the Mouse Model of Lyme Borreliosis

2000 ◽  
Vol 68 (11) ◽  
pp. 6457-6460 ◽  
Author(s):  
Mark S. Hanson ◽  
Nita K. Patel ◽  
David R. Cassatt ◽  
Nancy D. Ulbrandt
Keyword(s):  
Borrelia Burgdorferi ◽  
Outer Surface ◽  
Binding Protein ◽  
Protein A ◽  
Surface Protein ◽  
Outer Surface Protein A ◽  
Outer Surface Protein ◽  
Antigen Vaccine ◽  
Single Antigen

ABSTRACT Mice immunized with either the predominantly vector-stage lipoprotein outer surface protein A (OspA) or the in vivo-expressed lipoprotein decorin binding protein A (DbpA) are protected againstBorrelia burgdorferi challenge. DbpA-OspA combinations protected against 100-fold-higher challenge doses than did either single-antigen vaccine and conferred significant protection against heterologous B. burgdorferi, B. garinii, andB. afzelii isolates, suggesting that there is synergy between these two immunogens.

scholarly journals Decorin-Binding Protein A (DbpA) of Borrelia burgdorferi Is Not Protective When Immunized Mice Are Challenged via Tick Infestation and Correlates with the Lack of DbpA Expression by B. burgdorferi in Ticks

2000 ◽  
Vol 68 (8) ◽  
pp. 4759-4764 ◽  
Author(s):  
Kayla E. Hagman ◽  
Xiaofeng Yang ◽  
Stephen K. Wikel ◽  
George B. Schoeler ◽  
Melissa J. Caimano ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Murine Model ◽  
Blood Meal ◽  
Tick Infestation ◽  
Ixodes Scapularis ◽  
Binding Protein ◽  
Protein A ◽  
Lyme Disease Vaccine

ABSTRACT Previous studies showed that decorin-binding protein A (DbpA) ofBorrelia burgdorferi was a protective immunogen in the murine model of Lyme borreliosis when mice were challenged (needle inoculated) intradermally with in vitro-cultivated spirochetes. In the present study, DbpA-immunized C3H/HeJ mice were not protected from infection when infested with Ixodes scapularis nymphs harboring virulent B. burgdorferi 297. This lack of protection correlated with the failure to detect DbpA on B. burgdorferi in ticks, suggesting that DbpA is not available as a target for bactericidal antibodies in serum when B. burgdorferi-infected ticks take their blood meal from an immunized host. The failure of DbpA immunization to protect tick-challenged mice contradicts the results of earlier needle inoculation vaccination experiments and suggests that DbpA may not be suitable as a Lyme disease vaccine.

scholarly journals Engineering a fluorescence biosensor for the herbicide glyphosate

2020 ◽  
Vol 33 ◽  
Author(s):  
Pierre-Emmanuel Y N’Guetta ◽  
Maggie M Fink ◽  
Shahir S Rizk
Keyword(s):  
Binding Protein ◽  
Tap Water ◽  
Protein A ◽  
Binding Pocket ◽  
Soil Samples ◽  
Increased Risk ◽  
Water And Soil Samples ◽  
The Usa ◽  
Fluorescence Biosensor ◽  
Herbicide Glyphosate

Abstract Glyphosate, the active ingredient in RoundUp, is the most widely used herbicide on the globe, and has recently been linked to an increased risk in non-Hodgkin’s lymphoma in exposed individuals. Therefore, detection and monitoring of glyphosate levels in water and soil is important for public safety. Here, we describe a biosensor for glyphosate based on an engineered Escherichia coli phosphonate-binding protein (PhnD). Mutations in the binding pocket were introduced to convert PhnD into a glyphosate-binding protein. A fluorescence group attached near the hinge of the protein was added to monitor binding of glyphosate and to determine its concentration in unknown samples. The resulting engineered biosensor can detect glyphosate in tap water and in soil samples treated with the herbicide at submicromolar concentrations, well below the limit for drinking water in the USA. Incorporating this biosensor in a device would allow rapid and continuous monitoring of glyphosate in water and soil samples.

scholarly journals The BBA01 Protein, a Member of Paralog Family 48 from Borrelia burgdorferi, Is Potentially Interchangeable with the Channel-Forming Protein P13

2006 ◽  
Vol 188 (12) ◽  
pp. 4207-4217 ◽  
Author(s):  
Marija Pinne ◽  
Katrin Denker ◽  
Elin Nilsson ◽  
Roland Benz ◽  
Sven Bergström
Keyword(s):  
Borrelia Burgdorferi ◽  
Single Channel ◽  
Sequence Similarity ◽  
Shuttle Vector ◽  
Protein A ◽  
Gene Families ◽  
Wild Type ◽  
C Terminus ◽  
High Degree ◽  
Paralog Family

ABSTRACT The Borrelia burgdorferi genome exhibits redundancy, with many plasmid-carried genes belonging to paralogous gene families. It has been suggested that certain paralogs may be necessary in various environments and that they are differentially expressed in response to different conditions. The chromosomally located p13 gene which codes for a channel-forming protein belongs to paralog family 48, which consists of eight additional genes. Of the paralogous genes from family 48, the BBA01 gene has the highest homology to p13. Herein, we have inactivated the BBA01 gene in B. burgdorferi strain B31-A. This mutant shows no apparent phenotypic difference compared to the wild type. However, analysis of BBA01 in a C-terminal protease A (CtpA)-deficient background revealed that like P13, BBA01 is posttranslationally processed at its C terminus. Elevated BBA01 expression was obtained in strains with the BBA01 gene introduced on the shuttle vector compared to the wild-type strain. We could further demonstrate that BBA01 is a channel-forming protein with properties surprisingly similar to those of P13. The single-channel conductance, of about 3.5 nS, formed by BBA01 is comparable to that of P13, which together with the high degree of sequence similarity suggests that the two proteins may have similar and interchangeable functions. This is further strengthened by the up-regulation of the BBA01 protein and its possible localization in the outer membrane in a p13 knockout strain, thus suggesting that P13 can be replaced by BBA01.

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