Enhancing Proton-Coupled Electron Transfer in Blue Light Using FAD Photoreceptor AppA.

The Blue Light Using FAD (BLUF) photoreceptor utilizes a noncovalently bound FAD to absorb light and trigger the initial ultrafast events in receptor activation. FAD undergoes 1 and 2 electron reduction as an enzyme redox cofactor, and studies on the BLUF photoreceptor PixD revealed the formation of flavin radicals (FAD and FADH) during the photocycle, supporting a general mechanism for BLUF operation that involves PCET from a conserved Tyr to the oxidized FAD. However, no radical intermediates are observed in the closely related BLUF proteins AppA and BlsA, and replacing the conserved Tyr with fluoro-Tyr analogs that increase the acidity of the phenol OH has a minor effect on AppA photoactivation in contrast to PixD where the photocycle is halted at FAD.

Crystal structure of a bacterial photoactivated adenylate cyclase determined by serial femtosecond and serial synchrotron crystallography.

OaPAC is a recently discovered blue-light-using flavin adenosine dinucleotide (BLUF) photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata that uses adenosine triphosphate and translates the light signal into the production of cyclic adenosine monophosphate. Here, we report crystal structures of the enzyme in the absence of its natural substrate determined from room-temperature serial crystallography data collected at both an X-ray free-electron laser and a synchrotron, and we compare these structures with cryo-macromolecular crystallography structures obtained at a synchrotron by us and others. These results reveal slight differences in the structure of the enzyme due to data collection at different temperatures and X-ray sources.

Variability of theory of mind versus pragmatic ability in typical and atypical development.

Introduction: Numerous studies have linked deficits in Theory of Mind (ToM) with language problems. We aimed to explore the similarities and differences between children's patterns of performance on a ToM task that requires minimal linguistic skill and a pragmatic inference task that relies on both ToM and language. We assessed variability in pragmatic inference skills and ToM across populations of children (8-14 years) displaying varying cognitive profiles.

Exploring the Role of Neuropeptide PACAP in Cytoskeletal Function Using Spectroscopic Methods.

The behavior and presence of actin-regulating proteins are characteristic of various clinical diseases. Changes in these proteins significantly impact the cytoskeletal and regenerative processes underlying pathological changes. Pituitary adenylate cyclase-activating polypeptide (PACAP), a cytoprotective neuropeptide abundant in the nervous system and endocrine organs, plays a key role in neuron differentiation and migration by influencing actin.