The C-glycosyltransferase IroB from Pathogenic Escherichia coli: Identification of Residues Required for Efficient Catalysis

The E. coli C-glycosyltransferase IroB catalyzes formation of a C-C bond between enterobactin and the glucose moiety of UDP-glucose, resulting in the production of mono-, di- and tri-glucosylated enterobactin (MGE, DGE, TGE). To identify catalytic residues, we generated a homology model of IroB from aligned structures of two similar C-glycosyltransferases as templates. Superposition of our homology model onto the structure of a TDP-bound orthologue revealed residue W264 as a possible stabilizer of UDP-glucose. D304 in our model was located near the predicted site of the glucose moiety of UDP-glucose. A loop containing possible catalytic residues (H65, H66, E67) was found at the predicted enterobactin-binding site. We generated IroB variants at positions 65-67, 264, and 304 and investigated variant protein conformations and enzymatic activities. Variants were found to have Tm values similar to wild-type IroB. Fluorescence emission spectra of H65A/H66A, E67A, and D304N were superimposable with wild-type IroB. However, the emission spectrum of W264L was blue-shifted, suggesting solvent exposure of W264. While H65A/H66A retained activity (92% conversion of enterobactin, with MGE as a major product), all other IroB variants were impaired in their abilities to glucosylate enterobactin: E67A catalyzed partial (29%) conversion of enterobactin to MGE; W264L converted 55% of enterobactin to MGE; D304N was completely inactive. Activity-impaired variants were found to bind enterobactin with affinities within 2.5-fold of wild-type IroB. Given our outcomes, we propose that IroB W264 and D304 are required for binding and orienting UDP-glucose, while E67, possibly supported by H65/H66, participates in enterobactin/MGE/DGE deprotonation

Cardiorespiratory Fitness Is Associated with a Reduced Cardiovascular Risk in Occupational Groups with Different Working Conditions: A Cross-Sectional Study among Police Officers and Office Workers

Several studies reported a high prevalence of cardiovascular risk factors among police officers and office workers, and adequate cardiorespiratory fitness was reported to have protective effects in reducing cardiovascular risk. Therefore, the present study aimed to evaluate the effects of cardiorespiratory fitness on reducing cardiovascular risk factors in these occupational groups. This cross-sectional study enrolled 101 male participants (55 police officers and 46 office workers). Cardiorespiratory fitness was assessed via spiroergometry. Cardiovascular risk factors were also examined, and the 10-year cardiovascular risk and heart/vascular age were reported using the Framingham risk score. In both groups, higher cardiorespiratory fitness was associated with lower cardiovascular risk factors. Police officers and office workers with higher cardiorespiratory fitness demonstrated significantly lower values in BMI, waist circumference, body fat percentage, diastolic resting blood pressure, heart rate, triglycerides and total cholesterol values, and 10-year cardiovascular risk and heart/vascular age (all factors p < 0.0077, age adjusted). Police officers and office workers mostly presented low levels of cardiorespiratory fitness: 60% of police officers and 58% of office workers were considered “not fit and obese”. Despite different working conditions, both occupational groups had a high rate of low cardiorespiratory fitness levels and showed no differences in their cardiovascular risk profiles. In both groups, cardiorespiratory fitness reduced cardiovascular risk factors, but there was no difference in the influence of cardiorespiratory fitness on cardiovascular risk factors

Exercise capacity, cardiovascular and metabolic risk of the sample of German police officers in a descriptive international comparison

Background: The police force has the mandate to protect citizens and enforce the law for public safety. Employment in the police force is recognized as a dangerous occupation and characterized by job-related physical hazards. Therefore, good health and adequate physical condition are necessary. This study aimed to determine cardiovascular, cardiorespiratory, and metabolic risk parameters of German police officers (POs) in comparison to POs from other nations. Methods: 55 male police officers from Germany participated in the survey. We examined anthropometric measurements, cardiovascular/metabolic risk factors and blood parameters. Additionally, we calculated 10-year cardiovascular risk using the Framingham Risk Score. The diagnosis of metabolic syndrome bases on the criteria of the International Diabetes Federation. We assessed cardiorespiratory status by exercise spirometry. Results: The analyzed group of POs demonstrated a high prevalence of pre obesity (BMI: 28.0±3.2 kg/m², waist circumference: 97.8±12.4 cm). 61.8 % of POs showed an increased waist circumference. POs showed high prevalence of abnormal values of triglyceride (n: 24, 43,6%), and systolic (n: 29, 52,7%) and diastolic (n: 27, 49%) blood pressure. The average 10-year cardiovascular risk (by Framingham) was classified as moderate (9.6 ± 7.4 %). 32 % (n: 18) of POs in our study group were diagnosed with metabolic syndrome. Maximal relative oxygen uptake of POs was 34.1 ± 8.0 ·ml/kg-1 ·min-1. Conclusions: To our knowledge, this study was one of the first to assess data on cardiovascular health, metabolic syndrome and cardiorespiratory status of police officers in Germany. The results of our study demonstrated an increased cardiovascular and metabolic risk and decreased cardiorespiratory fitness in German police officers. The present study results underline the need to implement health-promoting interventions and concepts like corporate sports activities or nutrition courses to counteract cardiovascular and metabolic risk factors. We have to reduce the subsequent development of cardiovascular and metabolic disease in this occupational group

Occupation and metabolic syndrome: Is there correlation? A cross sectional study in different work activity occupations of German firefighters and office workers

The treatment and prevention of the metabolic syndrome (MetS) is currently one of the major challenges in medicine. The impact of working conditions on metabolic risk has not been adequately studied. Our objective was to compare the prevalence of MetS and metabolic risk in two extremely different occupational groups: firefighters and office workers. A total of 143 male subjects (97 firefighters and 46 office workers) from Germany participated in the study. Anthropometric characteristics, metabolic risk parameters as well as laboratory parameters were collected. MetS was diagnosed according to criteria of the International Diabetes Federation. Sedentary occupation showed a significant tendency towards obesity. Abdominal waist circumference was significantly greater in office workers than in firefighters [5.08 CI (1.44-8.71), p = 0.007]. Concerning metabolic risk factors, abnormal HDL, triglycerides, BMI, blood pressure and waist circumference values were more frequently found in office workers than in firefighters. The MetS was detected in almost 33 % of office workers as compared with only 14 % in firefighters (p = 0.015). Regarding MetS in an international comparison, the prevalence of MetS in German office workers was high and in firefighters it was extremely low. Sedentary occupation as an office worker is associated with a high risk of MetS. Both groups need to be made aware of the metabolic risks, and health promoting concepts such as corporate sports activities or education in healthy nutrition need to be implemented to counteract the development of the MetS and cardiovascular risk factors.Sin financiación2.347 JCR (2016) Q3, 92/138 Endocrinology and Metabolism1.006 SJR (2016) Q2, 77/244 Endocrinology, Diabetes and Metabolism, 43/144 Internal MedicineNo data IDR 2016UE

Metabolic Syndrome in Female Police Officers and Female Office Workers: A Cross-Sectional Study in Occupations with Different Physical Activities

Introduction: Increase in the prevalence of metabolic syndrome (MetS) has become a worldwide major health problem. So far, there are limited data about the impact of occupation types and the development of metabolic risks in females. This study aimed to compare the metabolic risk profiles and in two extremely different female occupational groups: police officers (PO) and office workers (OW). Methods: The prospective study included a total number of 97 female subjects (37 POs and 60 OWs) from Germany. Anthropometric characteristics, metabolic risk parameters as well as laboratory parameters were taken. The diagnosis of MetS was based on the criteria of the International Diabetes Federation (IDF). Results: Female OWs presented a high prevalence of obesity, shown in average abdominal waist circumference (85.3 ± 14.5 cm) above the threshold of ≥ 80 cm recommended by the IDF to define abdominal obesity. Sixty percent of OWs versus 25% of POs had an abnormal abdominal waist circumference. Concerning other metabolic risk factors (HDL, triglycerides, body mass index, blood pressure) no significant differences were found, but a tendency toward a higher prevalence of abnormal values is presented in OWs than POs. MetS was detected in almost 8% of OWs as compared with 5% in POs (p = 0.705). Conclusion: In an international comparison, German female POs showed one of the lowest prevalence of MetS, whereas the prevalence in OWs is equal to results in other countries. In conclusion, especially the occupational type of female OWs presented elevated factors, that are associated with increased metabolic risk. There is a relevant need for further prospective studies with larger sample sizes in female workers to determine the influence between occupational type and metabolic system

Cardiorespiratory Fitness Is Associated with a Reduced Cardiovascular Risk in Occupational Groups with Different Working Conditions: A Cross-Sectional Study among Police Officers and Office Workers

Several studies reported a high prevalence of cardiovascular risk factors among police officers and office workers, and adequate cardiorespiratory fitness was reported to have protective effects in reducing cardiovascular risk. Therefore, the present study aimed to evaluate the effects of cardiorespiratory fitness on reducing cardiovascular risk factors in these occupational groups. This cross-sectional study enrolled 101 male participants (55 police officers and 46 office workers). Cardiorespiratory fitness was assessed via spiroergometry. Cardiovascular risk factors were also examined, and the 10-year cardiovascular risk and heart/vascular age were reported using the Framingham risk score. In both groups, higher cardiorespiratory fitness was associated with lower cardiovascular risk factors. Police officers and office workers with higher cardiorespiratory fitness demonstrated significantly lower values in BMI, waist circumference, body fat percentage, diastolic resting blood pressure, heart rate, triglycerides and total cholesterol values, and 10-year cardiovascular risk and heart/vascular age (all factors p < 0.0077, age adjusted). Police officers and office workers mostly presented low levels of cardiorespiratory fitness: 60% of police officers and 58% of office workers were considered “not fit and obese”. Despite different working conditions, both occupational groups had a high rate of low cardiorespiratory fitness levels and showed no differences in their cardiovascular risk profiles. In both groups, cardiorespiratory fitness reduced cardiovascular risk factors, but there was no difference in the influence of cardiorespiratory fitness on cardiovascular risk factors