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.

Development of a flat jet delivery system for soft X-ray spectroscopy at MAX IV.

One of the most challenging aspects of X-ray research is the delivery of liquid sample flows into the soft X-ray beam. Currently, cylindrical microjets are the most commonly used sample injection systems for soft X-ray liquid spectroscopy. However, they suffer from several drawbacks, such as complicated geometry due to their curved surface.

Light-induced Trp/Met Switching During BLUF Domain Activation in ATP-bound Photoactivatable Adenylate Cyclase OaPAC.

The understanding of signal transduction mechanisms in photoreceptor proteins is essential for elucidating how living organisms respond to light as environmental stimuli. In this study, we investigated the ATP binding, photoactivation and signal transduction process in the photoactivatable adenylate cyclase from Oscillatoria acuminata (OaPAC) upon blue light excitation. Structural models with ATP bound in the active site of native OaPAC at cryogenic as well as room temperature are presented.

Mix-and-extrude: high-viscosity sample injection towards time-resolved protein crystallography.

Time-resolved crystallography enables the visualization of protein molecular motion during a reaction. Although light is often used to initiate reactions in time-resolved crystallography, only a small number of proteins can be activated by light. However, many biological reactions can be triggered by the interaction between proteins and ligands.

Gold nanoparticle-enhanced target for MS analysis and imaging of harmful compounds in plant, animal tissue and on fingerprint.

Gold nanoparticle-enhanced target (AuNPET) was used for detailed investigation of various materials of biological origin - human fingerprint, onion bulb and chicken liver. Analysis of these objects was focused on toxic and harmful compounds - designer drug containing pentedrone, diphenylamine in onion and potentially cancerogenic metronidazole antibiotic in liver. Detection of large quantity of endogenous compounds from mentioned objects is also shown.

High levels of RAD51 perturb DNA replication elongation and cause unscheduled origin firing due to impaired CHK1 activation.

In response to replication stress ATR signaling through CHK1 controls the intra-S checkpoint and is required for the maintenance of genomic integrity. Homologous recombination (HR) comprises a series of interrelated pathways that function in the repair of DNA double strand breaks and interstrand crosslinks. In addition, HR, with its key player RAD51, provides critical support for the recovery of stalled forks during replication.

Impact of homologous recombination on individual cellular radiosensitivity.

Purpose: Individual radiosensitivity as measured with in vitro irradiated lymphocytes using metaphase analysis can predict the risk of normal tissue effects after radiotherapy. This parameter is considered to be primarily determined by the cellular repair capacity of DNA double-strand breaks (DSBs). It is now tested to which extent this capacity also depends on homologous recombination (HR), which is a pathway available when cells are in S/G2 phase.

Lymphoblastoid cell lines differing in p53 status show clear differences in basal gene expression with minor changes after irradiation.

Background And Purpose: The genetic profile as determined by microarray is considered to be an ideal marker of the individual radiosensitivity. However, it is still an open question, whether this profile has to be determined prior to or only after irradiation, since the expression of some genes is affected by irradiation. These changes are induced mainly due to a p53-dependent transactivation.

[Promoter variants of aldosterone synthase gene (CYP11B2) and salt-sensitivity of blood pressure].

The T(-344)C polymorphism in promoter of CYP11B2 gene encoding aldosterone synthase has been associated with differences in plasma aldosterone (ALDO) concentrations. In addition, the results of recent study carried out in Japan suggest that C(-344) allele of CYP11B2 may be a genetic marker of salt-sensitive hypertension characterized by low plasma renin activity (PRA) and high ALDO/PRA ratio. Therefore, it raises the question of whether the T(-344)C polymorphism of CYP11B2 gene may be associated with salt-sensitive hypertension in Caucasians.

For X-irradiated normal human fibroblasts, only half of cell inactivation results from chromosomal damage.

Purpose: To study the relationship between residual double-strand breaks (dsbs), chromosomal damage, and cell inactivation for X-irradiated normal human fibroblasts.

Methods And Materials: The experiments were performed with 12 normal human fibroblast strains and, for comparison, a fibroblast line from a LiFraumeni patient (LFS2800), a squamous cell carcinoma line (FaDu), and CHO cells. Cells were irradiated in plateau phase, which was followed by immediate or delayed (14 h) plating.