2nd Midlands Biophysics Symposium at University of Nottingham

 

My poster:

Assembly and bundling of the bacterial Z-ring protein FtsZ

Abstract:

The bacterial cell division protein FtsZ is a homologue of eukaryotic tubulins that polymerizes in a GTP-dependent manner. On this poster, we present our assessment of FtsZ polymerization and its dynamic behaviour in real time by right angle light scattering using a spectrophotometer. Polymerization was very rapid, remaining constant for about 5 minutes. The final phase of the reaction is a fast decrease in light scattering, indicating net depolymerisation occurred as the GTP in the reaction has all been converted to GDP. The effects of GTP, pH, K⁺, and Mg²⁺ on FtsZ polymerization were studied as well. The length of the steady-state phase was proportional to the GTP concentration, and importantly, Mg²⁺ was required for GTP hydrolysis, but not for GTP binding. The second part of the poster shows the kinetics of inorganic phosphate (P_i) released from the GTP hydrolysis. The assay employs a fast and sensitive spectrophotometric assay that measures ¦¡¡¡¡¡ì¬¡¡¡¡ì¬A₃₆₀ between the substrate MESG (2-amino-6-mercapto-7-methylpurine riboside) and the products (ribose 1-phosphate and 2-amino-6-mercapto-7-methlpurine). At pH 6.5, approximate 90% of the P_i was released into the media within around 20 minutes of GTP addition. The effects of GTP, pH, K⁺, and Mg²⁺ were also studied, and they are consistent with the previous results.