Changes in the stability and biomechanics of P22 bacteriophage capsid during maturation

Publication date: Available online 15 March 2018 Source:Biochimica et Biophysica Acta (BBA) - General Subjects Author(s): Ravi Kant, Aida Llauró, Vamseedhar Rayaprolu, Shefah Qazi, Pedro J. de Pablo, Trevor Douglas, Brian Bothner The capsid of P22 bacteriophage undergoes a series of structural transitions during maturation that guide it from spherical to icosahedral morphology. The transitions include the release of scaffold proteins and capsid expansion. Although P22 maturation has been investigated for decades, a unified model that incorporates thermodynamic and biophysical analyses is not available. A general and specific model of icosahedral capsid maturation are of significant interest to theoreticians searching for fundamental principles as well as virologists and material scientists seeking to alter maturation to their advantage. To address this challenge, we have combined the results from orthogonal biophysical techniques including differential scanning fluorimetry, atomic force microscopy, circular dichroism, and hydrogen-deuterium exchange mass spectrometry. By integrating these results from single particle and population measurements, an energy landscape of P22 maturation from procapsid through expanded shell to wiffle ball emerged, highlighting the role of metastable structures and the thermodynamics guiding maturation. The propagation of weak quaternary interactions across symmetric elements of the capsid is a key component for stability in P22. A surpr...
Source: Biochimica et Biophysica Acta (BBA) General Subjects - Category: Biochemistry Source Type: research