NMR Characterization of Antigen A/C3 Binding in Streptococcus mutans

Albert Brotgandel

Authors:  Albert Brotgandel, Gwladys Riviere, Jeanine Brady, Joanna Long

Faculty Mentor:   Joanna Long

College:  College of Medicine


Streptococcus mutans has been studied extensively since it was first isolated from dental caries as the primary etiologic agent of human dental caries. WapA and Adhesin P1 are produced by S. mutans in the early stages of biofilm establishment when sucrose is not present. This enables S. mutans to anchor to the dental surface and create a site for biofilm formation that, if left untreated, can progress to becoming a dental carie. In this study we use NMR to characterize the interaction of two derivatives of WapA and Adhesin P1, named Antigen A (AgA) and C3, respectively. By understanding the binding of these two proteins, we are able to understand their potentially synergistic interaction during the formation of S. mutans biofilm. This understanding is applicable to the use of Antigen A and C3 as targets for biofilm inhibition as a way of improving the treatment of dental caries.

Poster Pitch

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14 Responses
  1. Mark Law

    I think understood some of these words 🙂 Sorry we don’t get to close the semester and the House Cup. What’s next for you?

    1. Albert Brotgandel

      Hello Dr. Law! Thanks for taking a look at my poster. I’ll be spending a year working with the lab I’m with while I’m applying for medical school.

  2. Joanna Long

    Nice poster and presentation, Albert. I can’t wait to see how this develops as AgA is assigned and structurally characterized!

  3. Albert Brotgandel

    Thank you everyone for stopping by! I have ended the Zoom call to look at other posters but if you comment questions I’ll be sure to answer them as soon as I can.

  4. Colby Tomasello

    Great work Albert! This S. mutans bacteria clearly has major implications on plenty of human suffering and inconvenience, and it is great to see your work on something that affects all of us. If this biofilm can be inhibited, does this have implications for companies that develop dental treatment and dental care? Thanks for presenting!

    1. Albert Brotgandel

      Thank you Colby. While there’s still a lot of work to do to identify inhibitors and understand their mechanisms, they could represent a novel avenue of treatment. Dental care has even gone beyond the individual in some cases such as with the fluoridation of water as a public health measure.

  5. Sidney Broome

    This was a very interesting presentation Albert! If I’m understanding correctly, it looks like you’re on the right track for understanding how to inhibit biofilms made by a cavity-causing bacteria which is awesome for people like me who love sweets and can be prone to cavities. Also, I’ve always been curious about the types of experiments that go into protein interactions, so thank you for sharing your work!

  6. Joey McGinn

    Albert this is such a thorough and informational presentation/poster! Though I don’t have the content knowledge to fully understand it, I am blown away by the amount of work I know has gone into this and your immense dedication.

  7. Alex Duong

    Great work Albert!

    I’m curious, what is the combined molecular weight of Antigen A/C3? I remember hearing at a seminar at some point that deuteration is sometimes necessary in doing solution NMR of large (25+ kDa) proteins and was wondering if, in future NMR studies of Antigen A/C3, this would be necessary?

    1. Albert Brotgandel

      Thanks Alex! Antigen A is ~35kDa and C3 is ~20kDa. So far we have been able to get good HSQC spectra of C3 and, more recently, good TROSY spectra of Antigen A when doing titrations without deuterating. We have yet to decide if deuteration is necessary for assignment experiments on Antigen A. Preliminary assignment experiments did not get adequate resolution but they also were on less concentrated samples than we are now able to create. Great question!