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Adams, H. R.

Publications and source records attributed to Adams, H. R..

2 recordsLinked to original sources

Longitudinal Exploration of Auditory Sensory-Perceptual Processing in CLN3 Disease (Juvenile Neuronal Ceroid Lipofuscinosis (Batten disease)): A High-Density Auditory Evoked Potential (AEP) Study.

BackgroundThere is currently limited information about sensory and perceptual abilities across the progression of CLN3 disease (Juvenile Neuronal Ceroid Lipofuscinosis; Batten disease), a recessively inherited lysosomal storage disorder and a leading cause of childhood neurodegeneration. Clinical symptoms include vision loss, motor impairments, and cognitive challenges, making it difficult to accurately assess neurocognitive and perceptual abilities. Thus, there is a critical need to identify objective biomarkers that can be used to inform disease progression and track treatment response in this population. MethodsThis exploratory study investigates longitudinal changes in auditory sensory perceptual processing in a small sample of individuals with genetically confirmed CLN3 disease (N=4; 3 male) compared to a cross-sectional sample of 60 neurotypical (NT) controls using high-density electroencephalography (EEG). We utilized a duration mismatch negativity (MMN) paradigm, identical to what has been used in our previous cross-sectional study. We examined the auditory evoked potentials (AEPs) of the standard tones across three different stimulus onset asynchrony conditions and examined the N1 and P2 components of the AEP. ResultsWe found age related differences in the amplitudes of the N1 and P2 components in individuals with CLN3 disease relative to NT controls. These amplitude differences were most notable in CLN3 disease when participants were presented with standard tones that had the slowest presentation rate. Specifically, N1 and P2 amplitudes were more negative than NT controls in childhood and adolescence and as CLN3 disease participants aged, the amplitude of the AEPs was greater than controls. Further, a more positive N1 amplitude during the longest stimulus presentation condition was associated with both reduced verbal intelligence and working memory abilities in CLN3 disease participants. ConclusionsOur preliminary findings parallel recently published work in a mouse model of CLN3 disease that showed both sex- and age-dependent disruptions in central auditory processing. Taken together, we demonstrate the utility of auditory EEG measures as a sensitive, objective and translational measure in CLN3 disease that may serve as a potential outcome measure useful in tracking disease progression. Continued work is needed in humans focused on sex-based differences and longitudinal changes of auditory processing in CLN3 disease.

neuroscience↗

Double crossed? Structural and computational studies of an unusual crosslinked heme in Methylococcus capsulatus cytochrome P460

Cytochromes P460 oxidise hydroxylamine within the nitrogen cycle and contain as their active site an unusual catalytic c-type heme where the porphyrin is cross-linked to the protein via a lysine residue in addition to the canonical cross links from cysteine residues. Understanding how enzymes containing P460 heme oxidise hydroxylamine into either nitrous oxide or nitric oxide has implications for climate change. Interestingly the P460 containing hydroxylamine oxidoreductase utilises a tyrosine cross link to heme and performs similar chemistry. Previous crystal structures of cytochrome P460 from Nitrosomonas europaea (NeP460) clearly show the existence of a single crosslink between the Nz atom of lysine and the heme porphyrin with mutagenesis studies indicating roles for the crosslink in positioning a proton transfer residue and/or influencing the distortion of the heme. Here we describe the evidence for a novel double cross link between lysine and heme in the cytochrome P460 from Methylococcus capsulatus (Bath). In order to understand the complexities of this enzyme system we applied high resolution structural biology approaches at synchrotron and XFEL sources paired with crystal spectroscopies. Linked to this we carried out QM/MM simulations that enabled the prediction of electronic absorption spectra providing a crucial validation to linking simulations and experimental structures. Our work demonstrates the feasibility of a double crosslink in McP460 and provides an opportunity to investigate how simulations can interact with experimental structures.

biochemistry↗