ATP-dependent conformational dynamics in a photoactivated adenylate cyclase revealed by fluorescence spectroscopy and small-angle X-ray scattering.

Structural insights into the photoactivated adenylate cyclases can be used to develop new ways of controlling cellular cyclic adenosine monophosphate (cAMP) levels for optogenetic and other applications. In this work, we use an integrative approach that combines biophysical and structural biology methods to provide insight on the interaction of adenosine triphosphate (ATP) with the dark-adapted state of the photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata (OaPAC). A moderate affinity of the nucleotide for the enzyme was calculated and the thermodynamic parameters of the interaction have been obtained.

The effects of detergents on the polymerization properties of actin.

Effects of some detergents-most frequently used in membrane raft studies-on the polymerization properties of actin were examined under in vitro and in vivo conditions, for protein and cellular investigations, respectively. Under in vitro conditions the polymerization rates were measured with pyrene-labeled actin. We found that polymerization rate depended on the detergent concentration by following either biphasic characteristics or only decreasing tendency.