Photoreactions and Structural Changes of Anabaena Sensory Rhodopsin

Anabaena sensory rhodopsin (ASR) is an archaeal-type rhodopsin found in eubacteria. The gene encoding ASR forms a single operon with ASRT (ASR transducer) which is a 14 kDa soluble protein, suggesting that ASR functions as a photochromic sensor by activating the soluble transducer. This article reviews the detailed photoreaction processes of ASR, which were studied by low-temperature Fourier-transform infrared (FTIR) and UV-visible spectroscopy. The former research reveals that the retinal isomerization is similar to bacteriorhodopsin (BR), but the hydrogen-bonding network around the Schiff base and cytoplasmic region is different. The latter study shows the stable photoproduct of the all-trans form is 100% 13-cis, and that of the 13-cis form is 100% all-trans. These results suggest that the structural changes of ASR in the cytoplasmic domain play important roles in the activation of the transducer protein, and photochromic reaction is optimized for its sensor function

Should We Assess Vitamin D Status in Pediatric Patients with Celiac Disease?

Copyright © 2019 ESPGHAN and NASPGHAN. All rights reserved. Objectives: Screening for vitamin D status in celiac disease (CD) has been recommended but the literature provides varying support. We sought to assess the vitamin D status in newly diagnosed children with CD and in a non-CD control population and relate them to vitamin D intake. Methods: In a cross-sectional study, serum 25-hydroxyvitamin D (25-OHD) levels were drawn in children with newly diagnosed CD and compared with pediatric outpatients with functional abdominal complaints. Anthropometric data as well as vitamin D intake based on milk and multivitamin ingestion were collected. Results: Thirty-eight newly diagnosed CD patients (10.4 ± 3.0 years old; 50% girls) and 82 controls (11.2 ± 4.2 years old; 58.5% girls) were studied. Both groups were similar except for average daily D intake and BMI. There was no statistical difference in mean 25-OHD levels between CD (26.4 ± 8.0 ng/mL) and controls (23.5 ± 8.2 ng/mL) [P ≤ 0.07]. Both groups had high percentages of suboptimal D status (65.8% CD and 79.3% controls). 25-OHD levels significantly correlated with age (r = -0.262; P \u3c 0.0038) and estimated vitamin D intake (r = 0.361; P \u3c 0.0001). Conclusions: No significant difference in 25-OHD levels was noted between newly diagnosed CD and controls, but inadequate 25-OHD levels were common in both. 25-OHD levels were highly associated with vitamin D intake demonstrating similar vitamin D absorption between patients and controls. As CD is associated with bone disease and D status is frequently low, efforts at optimizing D, such as screening levels at diagnosis need to be conducted