Diffusion-controlled reactions on spherical surfaces. Application to bacteriophage tail fiber attachment

Area of Science:

• Biophysics
• Molecular Biology
• Biochemistry

Background:

• Bacteriophage T4 uses tail fibers for host cell attachment.
• Whiskers are proposed to assist in tail fiber attachment kinetics.
• Understanding these interactions is crucial for viral infection mechanisms.

Purpose of the Study:

• To explore the kinetic implications of a model for whisker-mediated tail fiber attachment.
• To determine conditions under which whiskers accelerate tail fiber binding to baseplates.
• To investigate the role of rotational diffusion in this process.

Main Methods:

• Modeling of whisker-fiber complex formation and subsequent diffusion.
• Application of theories on orientational effects in diffusion-controlled reactions.
• Calculation of diffusion times on a spherical surface to a target site.

Main Results:

• Whisker-assisted attachment is accelerated if W-F complex formation is faster than direct B-F interaction.
• Rate enhancement is significant when the reaction half-angle for W-F is larger than for B-F.
• Diffusion time is dependent on the rotational diffusion coefficient and reaction geometry.

Conclusions:

• The proposed model provides a kinetic explanation for whisker-mediated acceleration of tail fiber attachment.
• Plausible parameter choices satisfy the conditions for rate enhancement.
• The diffusion model has broader applications in surface-mediated molecular interactions.