ABSTRACT
Aim: This study aimed to explore the relationship between typical dreams and the mental health of residents in village-in-city. Methods: This study used the Chinese version of the Typical Dreams Questionnaire and Symptom Checklist 90 (SCL-90) to investigate the mental health status and typical dream themes of 1,190 residents recruited through random sampling from a village-in-city in Xi'an. Correlation analysis, t-test, and binary regression analysis were performed on the data using SPSS 24.0. Results: The five most frequent dream themes among residents in the village-in-city were "falling"; "school, teacher, study"; "being chased but not physically injured"; "enjoying delicious food"; and "repeatedly trying to do something," in the given order. The most frequent dream theme with negative SCL-90 factors was "falling" and with positive SCL-90 factors was "school, teacher, study." Typical dreams on different themes were significantly correlated with SCL-90 factors. The theme of "enjoying delicious food" was not significantly associated with most factors in SCL-90.
ABSTRACT
Isocitrate dehydrogenase (IDH) can be divided into NAD+-dependent and NADP+-dependent types based on the coenzyme specificity. It is worth noting that some IDHs exhibit dual coenzyme specificity characteristics. Herein, a dual coenzyme-dependent IDH from Umbonibacter Marinipuiceus (UmIDH) was expressed, purified, and identified in detail for the first time. SDS-PAGE and Gel filtration chromatography analyses showed that UmIDH is an 84.7 kDa homodimer in solution. The Km values for NAD+ and NADP+ are 1800.0 ± 64.4 µM and 1167.7 ± 113.0 µM in the presence of Mn2+, respectively. Meanwhile, the catalytic efficiency (kcat/Km) of UmIDH is only 2.3-fold greater for NADP+ than NAD+. The maximal activity for UmIDH occurred at pH 8.5 (with Mn2+) or pH 8.7 (with Mg2+) and at 35 °C (with Mn2+ or Mg2+). Heat inactivation assay revealed that UmIDH sustained 50% of maximal activity after incubation at 57 °C for 20 min with either Mn2+ or Mg2+. Moreover, three putative core coenzyme binding residues (R345, L346, and V352) of UmIDH were evaluated by site-directed mutagenesis. This recent work identified a unique dual coenzyme-dependent IDH and achieved the groundbreaking bidirectional modification of this specific IDH's coenzyme dependence for the first time. This provides not only a reference for the study of dual coenzyme-dependent IDH, but also a basis for the investigation of the coenzyme-specific evolutionary mechanisms of IDH.
