The α--acetylgalactosaminidase from the probiotic bacterium (NagBb) belongs to the glycoside hydrolase family 129 and hydrolyzes the glycosidic bond of Tn-antigen (GalNAcα1-Ser/Thr). NagBb is involved in assimilation of-glycans on mucin glycoproteins by in the human gastrointestinal tract, but its catalytic mechanism has remained elusive because of a lack of sequence homology around putative catalytic residues and of other structural information. Here we report the X-ray crystal structure of NagBb, representing the first GH129 family structure, solved by the single-wavelength anomalous dispersion method based on sulfur atoms of the native protein. We determined ligand-free, GalNAc, and inhibitor complex forms of NagBb and found that Asp-435 and Glu-478 are located in the catalytic domain at appropriate positions for direct nucleophilic attack at the anomeric carbon and proton donation for the glycosidic bond oxygen, respectively. A highly conserved Asp-330 forms a hydrogen bond with the O4 hydroxyl of GalNAc in the -1 subsite, and Trp-398 provides a stacking platform for the GalNAc pyranose ring. Interestingly, a metal ion, presumably Ca, is involved in the recognition of the GalNAc -acetyl group. Mutations at Asp-435, Glu-478, Asp-330, and Trp-398 and residues involved in metal coordination (including an all-Ala quadruple mutant) significantly reduced the activity, indicating that these residues and the metal ion play important roles in substrate recognition and catalysis. Interestingly, NagBb exhibited some structural similarities to the GH101 endo-α--acetylgalactosaminidases, but several critical differences in substrate recognition and reaction mechanism account for the different activities of these two enzymes.
In recent decades, social network sites (SNSs) have become more popular and SNSs addiction has become a serious social problem. However, few studies have examined the effect of a person's internal working model (IWM) on addiction, which determine how attachment processes operate throughout the life course. This study aims at investigating the influence of IWMs and the psychological state, particularly loneliness and interpersonal trust, and of gender differences on addiction of SNSs in Japanese university students. Participants were 284 undergraduates in Japan (130 males, 154 females) who were evaluated with an original questionnaire about SNSs addiction, the UCLA Loneliness Scale, Interpersonal Trust Scale, and Internal Working Model Scale. We conducted multiple regression analyses by setting the entry method, one of which was forced entry, to examine the relationship between the dependent variable (SNSs addiction) and the independent variables (other factors) in each gender. The results show that SNSs addiction is influenced by an ambivalent attachment style (males, β = .19; females β = .36) and utilization time (males, β = .32; females β = .32) in both genders. To compare gender differences, we examined the structural equation modeling. The results show that only the influence of an ambivalent attachment style is significantly different between males and females (z = 5.04, p < .01), suggesting that such an attachment style predicts SNSs addiction. Because females tend to use SNSs as interaction tools, those with a high ambivalent style may become preoccupied with peer group membership. To prevent * Corresponding author. A. Fujimori et al. 1833 SNSs addiction, it is important that children form stable attachment relationships with parents/ caregivers when young. Regarding clinical implications, if counseling or psychotherapy is employed for people with SNSs addiction, it is important to assess the attachment style, and that therapy work toward changing an ambivalent style to a stable one.
Since it is supposed that the number of patients with dementia will increase as populations age in the near future, it is important to prevent dementia. In the present study, we examined whether acupuncture and life style improvements are able to enhance cognitive function.The subjects who worry about being forgetful were recruited and divided at random into two groups ; a group receiving acupuncture with transcutaneous electrical acupuncture-point stimulation (TEAS) and improvements in life style (20 subjects ; group A) and a group undergoing improvements in life style alone (20 subjects ; group B) for 12 weeks. The results showed that the cognitive functions assessed via a Mini-Mental State Examination (MMSE) and the Wechsler Memory Scale-Revised, sleep time, and sleep efficiency were improved in all subjects included in groups A and B after the interventions. There were significant pre-to post-intervention differences in MMSE and sleep efficiency in group A only. It was found that these interventions increased NK cells, NK activity and B cell numbers, and decreased T cell and helper T cell numbers. Thus, acupuncture and improvement of life style could enhance cognitive function and may be useful for the prevention of dementia.acupuncture, TEAS, cognitive function, actigraphy, immunity
In Japanese traditional medicine, "ganmenshin" (facial diagnosis), which means assessment of a patient's health based on the color of his/her face, is frequently used in a clinical setting. However, little scientific evidence is available to substantiate such diagnoses. In the present study, we investigated the relationship between skin color and patient's health status to ascertain the clinical usefulness of the "ganmenshin" technique. We evaluated the color of the cheeks and forearms of 30 healthy study participants and also administered questionnaires to determine their health. A correlation was observed between skin color and work efficiency and the inkyo (yin-fluid deficiency) scores in all subjects. In male subjects, skin color was correlated with their bodymass index (BMI), self-rated health status, work efficiency, and suitai (fluid stagnation) scores. In female subjects, skin color was correlated with the patient's age, work efficiency, and inkyo scores. These results suggest that "ganmenshin" may be clinically useful because of the correlation between skin color and the health of patients. skin color, health condition, ganmenshin, syakuhu, Japanese traditional medicine
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.