Lyme borreliosis is a multisystem disorder caused
by the spirochete Borrelia burgdorferi that is
transmitted to humans by the tick Ixodes dammini.
The immune response against the 31 kDa OspA, which is one
of the most abundant B. burgdorferi proteins,
appears to be critical in preventing infection and tissue
inflammation. Detailed knowledge of the immunological and
molecular characteristics of the OspA protein is important
for the development of reliable diagnostic assays. In this
study, we characterized a new conformational epitope present
within the middle part of B. burgdorferi OspA.
Our approach used enzymatic proteolyses of the immune complex
followed by mass spectrometric identification of the peptides
bound to the antibody. It appears to be one of the first
reports on the characterization of a discontinuous epitope
using mass spectrometry.