Precision Activity-Based α-Amylase Probes for Dissection and Annotation of Linear and Branched-Chain Starch-Degrading Enzymes.

α-Amylases are the workhorse enzymes of starch degradation. They are central to human health, including as targets for anti-diabetic compounds, but are also the key enzymes in the industrial processing of starch for biofuels, corn syrups, brewing and detergents. Dissection of the activity, specificity and stability of α-amylases is crucial to understanding their biology and allowing their exploitation.

Acarbose impairs gut growth by targeting intracellular glucosidases.

Unlabelled: Acarbose is a type 2 diabetes medicine that prevents dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading , (Bo), and (Bt).

Infections Following Gender-Affirming Vaginoplasty: A Single-Center Experience.

We describe the epidemiology and incidence of infections following gender-affirming vaginoplasty. Urinary tract and surgical site infections were the most common infections with incidences of 17.5% and 5.

Socio-ecological impacts of extreme weather events in two informal settlements in Nairobi, Kenya.

Climate change is expected to profoundly impact health and coping and widen social and environmental inequalities. People living in informal settlements are especially vulnerable to climate change as they are often located in ecologically sensitive areas more susceptible to extreme weather events (EWEs), such as floods, droughts, and heat waves. Women residing in informal settlements are especially vulnerable to climate change and related EWEs because they are more likely to experience worse health-related impacts than men but are less likely to have access to health-related services.

Acarbose Impairs Gut Growth by Targeting Intracellular GH97 Enzymes.

Acarbose is a type-2 diabetes medicine that inhibits dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading , (Bo) and (Bt).

Polycomb safeguards imaginal disc specification through control of the Vestigial-Scalloped complex.

A fundamental goal of developmental biology is to understand how cell and tissue fates are specified. The imaginal discs of Drosophila are excellent model systems for addressing this paradigm as their fate can be redirected when discs regenerate after injury or when key selector genes are misregulated. Here, we show that when Polycomb expression is reduced, the wing selector gene vestigial is ectopically activated.

BoGH13A from Bacteroides ovatus represents a novel α-amylase used for Bacteroides starch breakdown in the human gut.

Members of the Bacteroidetes phylum in the human colon deploy an extensive number of proteins to capture and degrade polysaccharides. Operons devoted to glycan breakdown and uptake are termed polysaccharide utilization loci or PUL. The starch utilization system (Sus) is one such PUL and was initially described in Bacteroides thetaiotaomicron (Bt).

Isothermal Titration Calorimetry for Quantification of Protein-Carbohydrate Interactions.

Isothermal titration calorimetry allows the determination of thermodynamic parameters for the interaction between a protein and mono- or oligosaccharides in solution. For the study of protein-carbohydrate interactions, it is a robust way to determine the stoichiometry and affinity, as well as the enthalpic and entropic contributions to this interaction, without the use of labeled proteins or substrates. Here we describe a standard multiple-injection titration experiment for measuring the binding energetics between a carbohydrate-binding protein and an oligosaccharide.

Polycomb safeguards imaginal disc specification through control of the Vestigial-Scalloped complex.

Unlabelled: A fundamental goal of developmental biology is to understand how cell and tissue fates are specified. The imaginal discs of are excellent model systems for addressing this paradigm as their fate can be redirected when discs regenerate after injury or when key selector genes are mis-regulated. Here, we show that when expression is reduced, the wing selector gene is ectopically activated.

A CUT&RUN protocol to determine patterns of epigenetic marks in imaginal discs of Drosophila.

Cleavage Under Targets & Release Using Nucleases (CUT&RUN) sequencing is a technique used to study gene regulation. The protocol presented here has been used successfully to identify the pattern of histone modifications within the genome of the eye-antennal disc of the fruit fly, Drosophila melanogaster. In its present form, it can be used to analyze genomic features of other imaginal discs.

Single-molecule dynamics of surface lipoproteins in bacteroides indicate similarities and cooperativity.

The gut microbiota comprises hundreds of species with a composition shaped by the available glycans. The well-studied starch utilization system (Sus) is a prototype for glycan uptake in the human gut bacterium Bacteroides thetaiotaomicron (Bt). Each Sus-like system includes outer-membrane proteins, which translocate glycan into the periplasm, and one or more cell-surface glycoside hydrolases, which break down a specific (cognate) polymer substrate.

Neoadjuvant cemiplimab for resectable hepatocellular carcinoma: a single-arm, open-label, phase 2 trial.

Background: Surgical resection of early stage hepatocellular carcinoma is standard clinical practice; however, most tumours recur despite surgery, and no perioperative intervention has shown a survival benefit. Neoadjuvant immunotherapy has induced pathological responses in multiple tumour types and might decrease the risk of postoperative recurrence in hepatocellular carcinoma. We aimed to evaluate the clinical activity of neoadjuvant cemiplimab (an anti-PD-1) in patients with resectable hepatocellular carcinoma.

Structure and substrate recognition by the Ruminococcus bromii amylosome pullulanases.

Pullulanases are glycoside hydrolase family 13 (GH13) enzymes that target α1,6 glucosidic linkages within starch and aid in the degradation of the α1,4- and α1,6- linked glucans pullulan, glycogen and amylopectin. The human gut bacterium Ruminococcus bromii synthesizes two extracellular pullulanases, Amy10 and Amy12, that are incorporated into the multiprotein amylosome complex that enables the digestion of granular resistant starch from the diet. Here we provide a comparative biochemical analysis of these pullulanases and the x-ray crystal structures of the wild type and the nucleophile mutant D392A of Amy12 complexed with maltoheptaose and 6-α-D glucosyl-maltotriose.

Structural and Functional Analysis of a Multimodular Hyperthermostable Xylanase-Glucuronoyl Esterase from .

The hyperthermophilic bacterium encodes an unusual enzyme, Xyn10C-GE15A, which incorporates two catalytic domains, a xylanase and a glucuronoyl esterase, and five carbohydrate-binding modules (CBMs) from families 9 and 22. The xylanase and glucuronoyl esterase catalytic domains were recently biochemically characterized, as was the ability of the individual CBMs to bind insoluble polysaccharides. Here, we further probed the abilities of the different CBMs from Xyn10C-GE15A to bind to soluble poly- and oligosaccharides using affinity gel electrophoresis, isothermal titration calorimetry, and differential scanning fluorimetry.

Minimal structural elements required for midline repulsive signaling and regulation of Drosophila Robo1.

The Roundabout (Robo) family of axon guidance receptors has a conserved ectodomain arrangement of five immunoglobulin-like (Ig) domains plus three fibronectin type III (Fn) repeats. Based on the strong evolutionary conservation of this domain structure among Robo receptors, as well as in vitro structural and domain-domain interaction studies of Robo family members, this ectodomain arrangement is predicted to be important for Robo receptor signaling in response to Slit ligands. Here, we define the minimal ectodomain structure required for Slit binding and midline repulsive signaling in vivo by Drosophila Robo1.

Host glycan utilization within the Bacteroidetes Sus-like paradigm.

The Bacteroidetes are numerically abundant Gram-negative organisms of the distal human gut with a greatly expanded capacity to degrade complex glycans. A subset of these are adept at scavenging host glycans within this environment, including mucin O-linked glycans, N-linked glycoproteins and highly sulfated glycosaminoglycans (GAGs) such as heparin (Hep) and chondroitin sulfate (CS). Several recent biochemical studies have revealed the specific polysaccharide utilization loci (PULs) within the model symbiont Bacteroides thetaiotaomicron for the deconstruction of these host glycans.

Are Fitbits implicated in body image concerns and disordered eating in women?

Objective: Using a daily monitoring framework, we examined the psychological consequences of Fitbit self-tracking on state body satisfaction, disordered eating (DE; i.e., binge eating and dietary restraint), levels of exercise engagement, and motivations (appearance vs.

Starch Digestion by Gut Bacteria: Crowdsourcing for Carbs.

Starch is a polymer of glucose and is one of the most abundant carbohydrates in a Western diet. Resistant starch escapes digestion by host small intestinal glucoamylases and transits the colon where it is degraded by the combined efforts of many gut bacteria. Bacterial metabolism and fermentation of resistant starch leads to increases in short-chain fatty acids, including the clinically beneficial butyrate.

Testes mass in the livebearing fish (Poeciliidae) varies hypoallometrically with body size but not between predation environments.

In this study, we considered potential causes of variation in testis size in the livebearing fish . We evaluated variation in testes mass among individual males and among populations that occupy different selective environments. First, we predicted that small males should allocate more to testes mass than large males (i.

The Mycobacterium tuberculosis complex has a pathway for the biosynthesis of 4-formamido-4,6-dideoxy-d-glucose.

Recent studies have demonstrated that the O-antigens of some pathogenic bacteria such as Brucella abortus, Francisella tularensis, and Campylobacter jejuni contain quite unusual N-formylated sugars (3-formamido-3,6-dideoxy-d-glucose or 4-formamido-4,6-dideoxy-d-glucose). Typically, four enzymes are required for the formation of such sugars: a thymidylyltransferase, a 4,6-dehydratase, a pyridoxal 5'-phosphate or PLP-dependent aminotransferase, and an N-formyltransferase. To date, there have been no published reports of N-formylated sugars associated with Mycobacterium tuberculosis.

Functional Analysis of Robo1 Fibronectin Type-III Repeats.

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate midline crossing of axons during development of the embryonic central nervous system (CNS). Slit proteins are produced at the midline and signal through Robo receptors to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline-crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Midline axon guidance in the Drosophila embryonic central nervous system.

Studies in the fruit fly Drosophila melanogaster have provided many fundamental insights into the genetic regulation of neural development, including the identification and characterization of evolutionarily conserved axon guidance pathways and their roles in important guidance decisions. Due to its highly organized and fast-developing embryonic nervous system, relatively small number of neurons, and molecular and genetic tools for identifying, labeling, and manipulating individual neurons or small neuronal subsets, studies of axon guidance in the Drosophila embryonic CNS have allowed researchers to dissect these genetic mechanisms with a high degree of precision. In this review, we discuss the major axon guidance pathways that regulate midline crossing of axons and the formation and guidance of longitudinal axon tracts, two processes that contribute to the development of the precise three-dimensional structure of the insect nerve cord.