1H, 13C and 15N backbone resonance assignments of the β-lactamase BlaP from Bacillus licheniformis 749/C and two mutational variants

Abstract

assignment of the wild-type BlaP (BlaP-WT) and of the two reference proteins, BlaP197Q0 and BlaP216Q0, wherein a Pro-Gly dipeptide has been introduced at position 197 and 216, respectively; this dipeptide originates from the addition of the Sma1 restriction site at the genetic level to allow further polyQ sequence insertion.Keywords BlaP hybrid proteins · Polyglutamine model proteins · Protein aggregation · Polyglutamine diseases · Resonance assignment Biological contextPolyglutamine (polyQ) diseases, including the well-known Huntington's disease and several spinocerebellar ataxias, are progressive and inherited neurodegenerative disorders associated with neural proteins that contain an 'expanded' polyQ sequence encoded by CAG trinucleotides repeats (Hands and Wyttenbach 2010). CAG repeats are present in the genes Abstract Class A β-lactamases have been widely used as versatile scaffolds to create hybrid (or chimeric) proteins for a series of applications ranging from basic research to medicine. We have, in particular, used the β-lactamase BlaP from Bacillus licheniformis 749/C (BlaP) as a protein scaffold to create model polyglutamine (polyQ) proteins in order to better understand the mechanism(s) by which an expanded polyQ sequence triggers the formation of amyloid fibrils. The model chimeras were designed by inserting a polyQ sequence of various lengths at two different locations within BlaP (i.e. position 197 or position 216) allowing a detailed comparison of the effects of subtle differences in the environment of the polyQ sequence on its ability to trigger protein aggregation. In order to investigate the effects of the polyQ insertion at both positions on the structure, stability and dynamics of BlaP, a series of NMR experiments including H/D exchange are foreseen. Accordingly, as necessitated by these studies, here we report the NMR David Thorn and Jennifer Kay have equally contributed to this work.