Cold sensitivity of the SARS-CoV-2 spike ectodomain

Area of Science:

• Virology
• Structural Biology
• Immunology

Background:

• The SARS-CoV-2 spike (S) protein is crucial for viral entry and a key target for COVID-19 vaccines.
• The Receptor Binding Domain (RBD) of the S protein exists in two distinct conformations: the 'up' (receptor-accessible) and 'down' (receptor-inaccessible) states.
• Understanding S protein structure and stability is vital for developing effective vaccines and therapeutics.

Approach:

• Investigated the temperature sensitivity of the commonly used 2P stabilized SARS-CoV-2 S ectodomain construct.
• Compared the cold sensitivity of the 2P construct with a stabilized 'down' state spike construct.
• Utilized structural and biophysical methods to analyze protein stability under varying temperatures.

Key Points:

• The 2P stabilized SARS-CoV-2 S ectodomain construct exhibits significant sensitivity to cold temperatures.
• This cold sensitivity is notably reduced or eliminated in a stabilized 'down' state spike construct.
• These findings highlight conformational and stabilization-dependent differences in S protein behavior.

Conclusions:

• The choice of SARS-CoV-2 S ectodomain construct and its stabilization method can influence its temperature sensitivity.
• Results provide critical insights for researchers using S protein constructs in structural, functional, and vaccine development studies.
• Optimizing S protein constructs for stability under various conditions is essential for reliable experimental outcomes.