36 research outputs found
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Bootstrapped Biocatalysis: Biofilm-Derived Materials as Reversibly Functionalizable Multienzyme Surfaces
Cell-free biocatalysis systems offer many benefits for chemical manufacturing, but their widespread applicability is hindered by high costs associated with enzyme purification, modification, and immobilization on solid substrates, in addition to the cost of the material substrates themselves. Here we report a “bootstrapped” biocatalysis substrate material that is produced directly in bacterial culture and is derived from biofilm matrix proteins, which self-assemble into a nanofibrous mesh. We demonstrate that this material can simultaneously purify and immobilize multiple enzymes site-specifically, and directly from crude cell lysates using a panel of genetically programmed, mutually orthogonal conjugation domains. We further demonstrate the utility of the technique in a bi- enzymatic stereoselective reduction coupled with cofactor recycling scheme. The domains allow for several cycles of selective removal and replacement of enzymes under mild conditions to regenerate the catalyst system.Engineering and Applied Science
Transcultural Diabetes Nutrition Therapy Algorithm: The Asian Indian Application
India and other countries in Asia are experiencing rapidly escalating epidemics of type 2 diabetes (T2D) and cardiovascular disease. The dramatic rise in the prevalence of these illnesses has been attributed to rapid changes in demographic, socioeconomic, and nutritional factors. The rapid transition in dietary patterns in India—coupled with a sedentary lifestyle and specific socioeconomic pressures—has led to an increase in obesity and other diet-related noncommunicable diseases. Studies have shown that nutritional interventions significantly enhance metabolic control and weight loss. Current clinical practice guidelines (CPGs) are not portable to diverse cultures, constraining the applicability of this type of practical educational instrument. Therefore, a transcultural Diabetes Nutrition Algorithm (tDNA) was developed and then customized per regional variations in India. The resultant India-specific tDNA reflects differences in epidemiologic, physiologic, and nutritional aspects of disease, anthropometric cutoff points, and lifestyle interventions unique to this region of the world. Specific features of this transculturalization process for India include characteristics of a transitional economy with a persistently high poverty rate in a majority of people; higher percentage of body fat and lower muscle mass for a given body mass index; higher rate of sedentary lifestyle; elements of the thrifty phenotype; impact of festivals and holidays on adherence with clinic appointments; and the role of a systems or holistic approach to the problem that must involve politics, policy, and government. This Asian Indian tDNA promises to help guide physicians in the management of prediabetes and T2D in India in a more structured, systematic, and effective way compared with previous methods and currently available CPGs
Could mitochondrial efficiency explain the susceptibility to adiposity, metabolic syndrome, diabetes and cardiovascular diseases in South Asian populations?
Background South Asians are susceptible to cardiovascular disease (CVD), especially after migration to affluent countries. Contributing factors include high prevalence of diabetes, and possibly insulin resistance. Excess adiposity centrally may underlie such metabolic disturbances. The thrifty genotype, thrifty phenotype, adipose tissue compartment and variable disease selection hypotheses are among the explanations posed.
Methods Data from individual studies and review articles known to the authors were examined. A Medline bibliographic database search was also performed. Reference lists were reviewed to identify additional relevant data sources. Key references were examined by both authors.
Results We propose, and evaluate, the evidence for a ‘mitochondrial efficiency hypothesis’ i.e. that ancestral changes in mitochondrial coupling efficiency enhanced the successful adaptation of South Asians to environmental stressors by maximizing the conversion of energy to adenosine triphosphate (ATP) rather than heat. This adaptation may be disadvantageous when South Asians are physically inactive and consume high-caloric diets. There is evidence that common mitochondrial mutations vary geographically. Mutations, including those affecting the function of mitochondrial uncoupling proteins (UCPs), may influence the balance of energy and heat production. These may influence basal metabolic rate (BMR), energy efficiency, the tendency to gain weight and hence metabolic disease. UCP gene polymorphisms are related to differences in BMR between African-Americans and Europeans. Similar data for South Asians are lacking but the few studies comparing BMR indicate that South Asians have a lower BMR, which is explained by a lower lean body mass, and higher fat mass. Once adjusted for body composition, BMR is similar. A high fat mass, per se, is a strategy for reducing energy use while conserving body size. Indians in the USA had higher oxidative phosphorylation capacity than Northern European Americans.
Conclusion The evidence justifies full exploration of this mitochondrial effeciency hypothesis in South Asians, which may also be relevant to other warm-climate adapted populations
Формирование эмоциональной культуры как компонента инновационной культуры студентов
Homozygosity has long been associated with rare, often devastating, Mendelian disorders1 and Darwin was one of the first to recognise that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3,4. Here we use ROH to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts and find statistically significant associations between summed runs of homozygosity (SROH) and four complex traits: height, forced expiratory lung volume in 1 second (FEV1), general cognitive ability (g) and educational attainment (nominal p<1 × 10−300, 2.1 × 10−6, 2.5 × 10−10, 1.8 × 10−10). In each case increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing convincing evidence for the first time that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5,6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein (LDL) cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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Modulating bacterial and gut mucosal interactions with engineered biofilm matrix proteins
Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors. Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins
Scalable Production of Genetically Engineered Nanofibrous Macroscopic Materials via Filtration
As
interest in using proteins to assemble functional, biocompatible,
and environmentally friendly materials is growing, developing scalable
protocols for producing recombinant proteins with customized functions
coupled to straightforward fabrication processes is becoming crucial.
Here, we use <i>E. coli</i> bacteria to produce amyloid
protein nanofibers that are key constituents of the biofilm extracellular
matrix and show that protein nanofiber aggregates can be purified
using a fast and easily accessible vacuum filtration procedure. With
their extreme resistance to heat, detergents, solvents, and denaturing
agents, engineered curli nanofibers remain functional throughout the
rigorous processing and can be used to assemble macroscopic materials
directly from broth culture. As a demonstration, we show that engineered
curli nanofibers can be fabricated into self-standing films while
maintaining the functionality of various fused domains that confer
new specific binding activity to the material. We also demonstrate
that purified curli fibers can be disassembled, reassembled into thin
films, and recycled for further materials processing. Our scalable
approach, which combines established purification techniques for amyloid
fibers, is applicable to a new class of recombinant amyloid proteins
whose sequence can be easily tailored for diverse applications through
genetic engineering
Portable, On-Demand Biomolecular Manufacturing
Synthetic biology uses living cells as molecular foundries for the biosynthesis of drugs, therapeutic proteins, and other commodities. However, the need for specialized equipment and refrigeration for production and distribution poses a challenge for the delivery of these technologies to the field and to low-resource areas. Here, we present a portable platform that provides the means for on-site, on-demand manufacturing of therapeutics and biomolecules. This flexible system is based on reaction pellets composed of freeze-dried, cell-free transcription and translation machinery, which can be easily hydrated and utilized for biosynthesis through the addition of DNA encoding the desired output. We demonstrate this approach with the manufacture and functional validation of antimicrobial peptides and vaccines and present combinatorial methods for the production of antibody conjugates and small molecules. This synthetic biology platform resolves important practical limitations in the production and distribution of therapeutics and molecular tools, both to the developed and developing world.Defense Threat Reduction Agency (DTRA) (Grant HDTRA1-14-1-0006