The crystal structure of Escherichia coli maltodextrin phosphorylase provides an explanation for the activity without control in this basic archetype of a phosphorylase.

In animals, glycogen phosphorylase (GP) exists in an inactive (T state) and an active (R state) equilibrium that can be altered by allosteric effectors or covalent modification. In Escherichia coli, the activity of maltodextrin phosphorylase (MalP) is controlled by induction at the level of gene expression, and the enzyme exhibits no regulatory properties. We report the crystal structure of E. coli maltodextrin phosphorylase refined to 2.4 A resolution. The molecule consists of a dimer with 796 amino acids per monomer, with 46% sequence identity to the mammalian enzyme. The overall structure of MalP shows a similar fold to GP and the catalytic sites are highly conserved. However, the relative orientation of the two subunits in E. coli MalP is different from both the T and R state GP structures, and there are significant changes at the subunit-subunit interfaces. The sequence changes result in loss of each of the control sites present in rabbit muscle GP. As a result of the changes at the subunit interface, the 280s loop, which in T state GP acts as a gate to control access to the catalytic site, is held in an open conformation in MalP. The open access to the conserved catalytic site provides an explanation for the activity without control in this basic archetype of a phosphorylase.     

Aquakultur – quo vadis?!

Aquaculture – quo vadis? Aquaculture is more than just fish production; it is a globally active sector of the food production industry. The production methods interact in different degrees with the environment, resulting in possible negative impact. Through enhancement of the production systems as well as utilized resources, such influence can be controlled and minimized. This includes the amount of water consumption, nutrient efficiency and thus nutrient excretion from the production systems. An optimization of the culture conditions has direct benefits for animal welfare, diseases resistance, product quality and consequently supporting the productivity of the aquaculture enterprises. Further support and networking of the stakeholders involved in education, research and private companies within the respective fields is required to reach the overall goal of an ecologically and economically sustainable aquaculture.     

Gastric bypass surgery reveals independency of obesity and diabetes melitus type 2

Background

Roux-en-Y gastric bypass surgery is widely applied to ameliorate morbid obesity, including diabetes in people with type 2 diabetes. The latter vanish a few days after surgery for many, but not in all patients before any weight reduction has occurred. The explanation for this change in metabolic status is poorly understood, but the observation may suggest that the fate obesity and diabetes is only partly linked after surgery.

Methods

The trajectories of weight reduction measured as reduced body mass index (BMI) in 741obese subjects with and without diabetes were evaluated. Evaluation was performed on three groups: 1) subjects that were non-diabetic before and after surgery; 2) subjects that were diabetics before surgery but non-diabetics after surgery; and 3) subjects that were diabetics before surgery and remained diabetics after surgery. The diabetic state was established at HbA1c above 48 mmol/mol.

Results

The trajectories differ significantly between groups and any sub-populations of groups, the latter identified by the distance between individual trajectories using a k-means procedure. The results suggest that different domains in the enormous genetic network governing basic metabolism are perturbed in obesity and diabetes, and in fact some of the patients are affected by two distinct diseases: obesity and diabetes mellitus type 2.

Conclusion

Although RYGB “normalized” many glycaemic parameters in some of the diabetic subjects apparently converting to a non-diabetics state, other diabetic subjects stay diabetic in the context of the new gut anatomy after surgery. Thus, the obesity part of the glycaemic derangement may have been ameliorated, but some defects of the diabetic state had not.

     

Lack of a Negative Effect of BCG-Vaccination on Child Psychomotor Development: Results from the Danish Calmette Study - A Randomised Clinical Trial

ObjectivesTo assess the non-specific effect of Bacillus Calmette-Guérin (BCG) vaccination at birth on psychomotor development.DesignThis is a pre-specified secondary outcome from a randomised, clinical trial.SettingMaternity units and paediatric wards at three university hospitals in Denmark.ParticipantsChildren born at gestational age (GA) 32 weeks and above. All women planning to give birth at the three sites were invited during the recruitment period. Out of 4262 randomised children, 144 were premature (GA < 37 weeks). There were 2129 children (71 premature) randomised to BCG and 2133 randomised (73 premature) to the control group.InterventionsBCG vaccination 0.05 ml was given intradermally in the upper left arm at the hospital within seven days of birth. Children in the control group did not receive any intervention. Parents were not blinded to allocation.ResultsThe mean difference in ASQ score at 12 months adjusted for age and prematurity was -0.7 points (BCG vs. control, 95% confidence interval; -3.7 to 2.4), p = 0.67, corresponding to an effect size of Cohen’s d = -0.015 (-0.082 to 0.052). The mean difference in ASQ score for premature children at 22 months was -7.8 points (-20.6 to 5.0, p = 0.23), d = -0.23 (-0.62 to 0.15).ConclusionsA negative non-specific effect of BCG vaccination at birth on psychomotor development was excluded in term children.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01694108","term_id":"NCT01694108"}}NCT01694108     

Effect of a Medicinal Agaricus blazei Murill-Based Mushroom Extract,AndoSan?, on Symptoms,Fatigue and Quality of Life in Patients with Ulcerative Colitis in a Randomized Single-Blinded Placebo Controlled Study

Background

Ingestion of AndoSan^™, based on the mushroom Agaricus blazei Murill, has previously been shown to exhibit anti-inflammatory effects because of reduction of pro-inflammatory cytokines in healthy individuals and patients with ulcerative colitis. In this randomized single-blinded placebo controlled study we examined whether intake of AndoSan^™ also resulted in clinical effects.

Methods and Findings

50 patients with symptomatic ulcerative colitis were block-randomized and blinded for oral daily intake of AndoSan^™ or placebo for the 21 days’ experimental period. The patients reported scores for symptoms, fatigue and health related quality of life (HRQoL) at days 0, 14 and 21. Fecal calprotectin and general blood parameters were also analyzed. In the AndoSan^™ group (n = 24) symptoms improved from baseline (day 0) to days 14 and 21, with respective mean scores (95% CI) of 5.88 (4.92–6.83), 4.71 (3.90–5.52) (p = 0.002) and 4.50 (3.70–5.30) (p = 0.001). Corresponding improved mean scores (±SD) for total fatigue were 16.6 (5.59), 14.1 (4.50) (p = 0.001) and 15.1 (4.09) (p = 0.023). These scores in the placebo group (n = 26) were not improved. When comparing the two study groups using mixed model statistics, we found significant better scores for the AndoSan^™-patients. HRQoL for dimensions bodily pain, vitality, social functioning and mental health improved in the AndoSan^™ group. There were no alterations in general blood samples and fecal calprotectin.

Conclusions

Beneficiary effects on symptoms, fatigue and HRQoL from AndoSan^™ consumption were demonstrated in this per-protocol study, supporting its use as a supplement to conventional medication for patients with mild to moderate symptoms from ulcerative colitis. The patients did not report any harms or unintended effects of AndoSan^™ in this study.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01496053","term_id":"NCT01496053"}}NCT01496053     

On the isolation, characterisation, and crystallisation of a human Bence-Jones protein of kappa type

The isolation and purification of the human Bence-Jones protein Rei is described. Physico-chemical data are given characterising the protein. It is shown that the protein could be crystallised. It is intended to use the crystals for single crystal X-ray diffraction studies.     

Small-angle X-ray scattering study of the (Fab′)2 fragment of the human immunoglobulin Kol

The conformation of the (Fab′)₂ fragment of the human immunoglubulin Kol has been investigated in solution by small angle X-ray scattering. The following molecular parameters were determined: radius of gyration 4.10 ± 0.05 nm; maximum distance 14.0 ± 0.5 nm and hydrated volume 150 ± 8 nm³. A model of the fragment is presented, which fits these experimental data and shows good agreement with the distance distribution function in real space and the scattering curve in reciprocal space. We have to assume that the (Fab′)₂ fragment has many different conformations in solution. The method of small-angle X-ray scattering only allows the determination of an average conformation which is very similar within the resolution of the method to the static structure determined in the crystal.