The allosteric transition of the chaperonin groel fromescherichia coli as studied by solution X-ray scattering

Abstract

This is a short review article of our recent studies on the ATP-induced, allosteric conformational transition of the chaperonin GroEL complex by solution X-ray scattering. We used synchrotron X-ray scattering with a twodimensional, charge-coupled, device-based X-ray detector to study (1) the specificity of the chaperonin GroEL for its ligand that induced the allosteric transition, and (2) the identification of the allosteric transition of GroEL in its complicated kinetics induced by ATP. Due to the dramatically increased sensitivity of the X-ray scattering technique based on the use of the two dimensional X-ray detector and synchrotron radiation, different allosteric conformational states of GroEL populated under different conditions were clearly distinguished from each other. It was concluded that solution X-ray scattering is an extremely powerful tool for investigating the equilibrium and kinetics of cooperative conformational transitions of oligomeric protein complex, especially when combined with other spectroscopic techniques such as fluorescence spectroscopy.

X-ray scattering studies on molecular structures of star and dendritic polymers

“…The scattering intensity I(q) from globular particles in a solvent medium can be expressed in the following: 18,23,[25][26][27][28][29] (1) where k is a constant, N is the number of particles, P(q) is the form factor of single particle, and S(q) is the structure factor: here q is the magnitude of scattering vector which is defined by q = 4π sinθ/λ where 2θ is the scattering angle. The term P(q) provides information on the particle shape and size while the term S(q) provides the inter-particle distances in the solution.…”