Catalytic enzymes are active matter

Using a microscopic theory to analyze experiments, we demonstrate that enzymes are active matter. Superresolution fluorescence measurements—performed across four orders of magnitude of substrate concentration, with emphasis on the biologically relevant regime around or below the Michaelis–Menten constant—show that catalysis boosts the motion of enzymes to be superdiffusive for a few microseconds, enhancing their effective diffusivity over longer timescales. Occurring at the catalytic turnover rate, these fast ballistic leaps maintain direction over a duration limited by rotational diffusion, driving enzymes to execute wormlike trajectories by piconewton forces performing work of a few kBT against viscosity. The boosts are more frequent at high substrate concentrations, biasing the trajectories toward substrate-poor regions, thus exhibiting antichemotaxis, demonstrated here experimentally over a wide range of aqueous concentrations. Alternative noncatalytic, passive mechanisms that predict chemotaxis, cross-diffusion, and phoresis, are critically analyzed. We examine the physical interpretation of our findings, speculate on the underlying mechanism, and discuss the avenues they open with biological and technological implications. These findings violate the classical paradigm that chemical reaction and motility are distinct processes, and suggest reaction–motion coupling as a general principle of catalysis.11sciescopu

Enzyme leaps fuel antichemotaxis

There is mounting evidence that enzyme diffusivity is enhanced when the enzyme is catalytically active. Here, using superresolution microscopy [stimulated emission-depletion fluorescence correlation spectroscopy (STED-FCS)], we show that active enzymes migrate spontaneously in the direction of lower substrate concentration (???antichemotaxis???) by a process analogous to the run-and-tumble foraging strategy of swimming microorganisms and our theory quantifies the mechanism. The two enzymes studied, urease and acetylcholinesterase, display two families of transit times through subdiffraction-sized focus spots, a diffusive mode and a ballistic mode, and the latter transit time is close to the inverse rate of catalytic turnover. This biochemical information-processing algorithm may be useful to design synthetic self-propelled swimmers and nanoparticles relevant to active materials. Executed by molecules lacking the decision-making circuitry of microorganisms, antichemotaxis by this run-and-tumble process offers the biological function to homogenize product concentration, which could be significant in situations when the reactant concentration varies from spot to spot

Measurement of epigenetic alterations from patient’s tissues in myoma, adenomyoma and endometriosis

Background: Myoma, adenomyoma, and endometriosis are estrogen-dependent gynecologic diseases and result in reproductive dysfunction and pelvic pain in women. However, these gynecologic diseases have a complex and poorly understood etiology, involving both genetic and environmental factors. Epigenetic alterations, heritable changes that can modify gene expression without affecting genetic sequence, are associated with the development and progression of numerous pathological states and diseases. Therefore, there is great potential for the use of epigenetics as biomarkers to better understand the early-stage biological responses and molecular mechanisms of gynecologic diesases. We aimed to examine levels of global DNA and gene-specific methylation, which are epigenetic alterations that could be associated with development of gynecologic diseases, including myoma, adenomyoma, and endometriosis. Methods: We measured global DNA methylation (LINE-1) as well as disease relevant gene-specific methylation (i.e. ER, PR, and aromatase) using pyrosequencing assay. For this measurement, gene-specific primers for the selected genes were designed using the Pyro-Mark assay design software. Genomic DNAs from each tissue were extracted, and underwent bisulfite modification to convert unmethylated cytosine residues to uracil. A Pyromark Q96 MD was used for all subsequent pyrosequencing. Samples were processed in duplicates on plates with water controls. Percent methylation of a sample was calculated by averaging all of the interrogated CpG sites. Results: Different methylation levels of selected genes were measured from myoma, adenomyoma, and endometriosis tissues. Our obtained results suggest that epigenetic changes are involved in development of different types of gynecologic diseases

Calpain-mediated proteolysis of polycystin-1 C-terminus induces JAK2 and ERK signal alterations

AbstractAutosomal dominant polycystic kidney disease (ADPKD), a hereditary renal disease caused by mutations in PKD1 (85%) or PKD2 (15%), is characterized by the development of gradually enlarging multiple renal cysts and progressive renal failure. Polycystin-1 (PC1), PKD1 gene product, is an integral membrane glycoprotein which regulates a number of different biological processes including cell proliferation, apoptosis, cell polarity, and tubulogenesis. PC1 is a target of various proteolytic cleavages and proteosomal degradations, but its role in intracellular signaling pathways remains poorly understood. Herein, we demonstrated that PC1 is a novel substrate for μ- and m-calpains, which are calcium-dependent cysteine proteases. Overexpression of PC1 altered both Janus-activated kinase 2 (JAK2) and extracellular signal-regulated kinase (ERK) signals, which were independently regulated by calpain-mediated PC1 degradation. They suggest that the PC1 function on JAK2 and ERK signaling pathways might be regulated by calpains in response to the changes in intracellular calcium concentration

Enzyme leaps fuel antichemotaxis

There is mounting evidence that enzyme diffusivity is enhanced when the enzyme is catalytically active. Here, using superresolution microscopy [stimulated emission-depletion fluorescence correlation spectroscopy (STED-FCS)], we show that active enzymes migrate spontaneously in the direction of lower substrate concentration (???antichemotaxis???) by a process analogous to the run-and-tumble foraging strategy of swimming microorganisms and our theory quantifies the mechanism. The two enzymes studied, urease and acetylcholinesterase, display two families of transit times through subdiffraction-sized focus spots, a diffusive mode and a ballistic mode, and the latter transit time is close to the inverse rate of catalytic turnover. This biochemical information-processing algorithm may be useful to design synthetic self-propelled swimmers and nanoparticles relevant to active materials. Executed by molecules lacking the decision-making circuitry of microorganisms, antichemotaxis by this run-and-tumble process offers the biological function to homogenize product concentration, which could be significant in situations when the reactant concentration varies from spot to spot

Experimental Study on the Acellular Demal Matrix Graft for the Root Coverage in Dog

Mucogingival surgery is a plastic surgical procedure designed to correct defects in the morphology, position, and dimensions of the gingiva surrounding the teeth. Many surgical techniques have been reported in mucogingival surgery. Since these procedures also include the soft tissue esthetic approach, the term periodontal plastic surgery has been proposed to be more appropriate.1 Root coverage is a procedure that falls with this definition, and it has attracted more interest than others

Central Venous Stenosis Caused by Traction of the Innominate Vein due to a Tuberculosis-Destroyed Lung

We report a case of central venous stenosis due to a structural deformity caused by a tuberculosis-destroyed lung in a 65-year-old woman. The patient presented with left facial edema. She had a history of pulmonary tuberculosis, and the chest X-ray revealed a collapsed left lung. Angiography showed leftward deviation of the innominate vein leading to kinking and stenosis of the internal jugular vein. Stent insertion improved her facial edema

An Infrarenal Aortic Hypoplasia Presented with Claudication

We describe a case of infrarenal aortic hypoplasia in a 52-yr-old woman who presented with claudication. Computed tomographic angiography revealed an abrupt absence of the infrarenal aorta, with collateral flow reconstituting the iliofemoral systems. After a polytetrafluoroethylene graft was interposed between the aortic stump and the iliac bifurcation, the patient's claudication resolved