Search results for " Interaction"

Thermodynamic analysis of the interactions between human ACE2 and spike RBD of Betacoronaviruses (SARS-CoV-1 and SARS-CoV-2)

2023

There are many scientific reports on the interaction of the SARS-CoV-2 virus S protein (and its RBD) with the human ACE2 receptor protein. However, there are no reliable data on how this interaction differs from the interaction of the receptor binding domain of SARS-CoV-1 with ACE2, in terms of binding strength and changes in reaction enthalpy and entropy. Our studies have revealed these differences and the impact of zinc ions on this interaction. Intriguingly, the binding affinity of both RBDs (of SARS-CoV-1 and of SARS-CoV-2) to the ACE2 receptor protein is almost identical; however, there are some differences in the entropic and enthalpic contributions to these interactions.

Force probe measurements of antibody-antigen interactions.

2000

The surface force apparatus has been used to quantify directly the forces that govern the interactions between proteins and ligands. In this work, we describe the measured interactions between the antigen fluorescein and the Fab' fragment of the monoclonal 4-4-20 anti-fluorescyl IgG antibody. Here we first describe the use of the surface force apparatus to demonstrate directly the impact of the charge composition in the region of the antibody binding site on the antibody interactions. Several approaches are described for immobilizing antigens, antibodies, and proteins in general for direct force measurements. The measured force profiles presented are accompanied by an extensive discussion o…

1993

Lobsters and dolphins are adapted to aquatic life whereas the green woodpecker and the fly are adapted to aerial life. The way in which these organisms are constructed allows them to execute certain functions within certain environments. This is a first, simple definition of adaptation which describes:The evolutionary process of adjustment of an organism to its environment. This historical aspect will be discussed in subsequent chapters.The result of this process — the state of adaptation — or the form of an organism at a certain point in its history. This functional-structural aspect will be dealt with here.

Conformational dynamics of full-length inducible human Hsp70 derived from microsecond molecular dynamics simulations in explicit solvent

2013

Human 70 kDa heat shock protein (hHsp70) is an ATP-dependent chaperone and is currently an important target for developing new drugs in cancer therapy. Knowledge of the conformations of hHsp70 is central to understand the interactions between its nucleotide-binding domain (NBD) and substrate-binding domain (SBD) and is a prerequisite to design inhibitors. The conformations of ADP-bound (or nucleotide-free) hHsp70 and ATP-bound hHsp70 was investigated by using unbiased all-atom molecular dynamics (MD) simulations of homology models of hHsp70 in explicit solvent on a timescale of .5 and 2.7 μs, respectively. The conformational heterogeneity of hHsp70 was analyzed by computing effective free-e…

Online Hate Does Not Stay Online – How Implicit and Explicit Attitudes Mediate the Effect of Civil Negativity and Hate in User Comments on Prosocial …

2020

Abstract Incivility and hateful language in user comments are met with growing concern among politicians, the general public, and scholars. There are fears that such comments may decrease social cohesion and ultimately result in less prosocial behavior among citizens. We investigate whether hate, or even civil negativity in user comments alone, inhibit actual prosocial behavior through recipients’ explicit and implicit attitudes. In an online experiment, 253 participants read user comments (neutral, civil-negative, hateful) about refugees and received five Euros which they could donate for a refugee aid organization or keep for themselves. The results show that participants confronted with …

Novel structural insights into F-actin-binding and novel functions of calponin homology domains.

2008

Tandem calponin homology (CH) domains are well-known actin filaments (F-actin) binding motifs. There has been a continuous debate about the details of CH domain-actin interaction, mainly because atomic level structures of F-actin are not available. A recent electron microscopy study has considerably advanced our structural understanding of CH domain:F-actin complex. On the contrary, it has recently also been shown that CH domains can bind other macromolecular systems: two CH domains from separate polypeptides Ncd80, Nuf2 can form a microtubule-binding site, as well as tandem CH domains in the EB1 dimer, while the single C-terminal CH domain of alpha-parvin has been observed to bind to a alp…

Unraveling biotic interactions determining soil microbial community assembly and functioning

2019

National audience; Microbial communities are at the heart of all ecosystems and yet, a sound understanding of the ecological processes governing the assembly of these communities in the environment is missing. To address the role of biotic interactions in assembly and functioning of the soil microbiota, we used a top down manipulation approach based on the removal of various populations in a natural microbial community. Suspensions of the soil microbiota were subjected to various biocidal and filtration treatments before being inoculated into the same sterilized soil. We hypothesized that if biotic interactions are an important shaping force of the microbiota assembly, removal of microbial …

Treatment with soluble activin type IIB-receptor improves bone mass and strength in a mouse model of Duchenne muscular dystrophy

2017

Background: Inhibition of activin/myostatin pathway has emerged as a novel approach to increase muscle mass and bone strength. Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to progressive muscle degeneration and also high incidence of fractures. The aim of our study was to test whether inhibition of activin receptor IIB ligands with or without exercise could improve bone strength in the mdx mouse model for DMD. Methods: Thirty-two mdx mice were divided to running and non-running groups and to receive either PBS control or soluble activin type IIB-receptor (ActRIIB-Fc) once weekly for 7 weeks. Results: Treatment of mdx mice with ActRIIB-Fc resulted in significantly…

Barbed Dental Ti6Al4V Alloy Screw : Design and Bench Testing

2023

Background context. Dental implants are designed to replace a missing tooth. Implant stability is vital to achieving osseointegration and successful implantation. Although there are many implants available on the market, there is room for improvement. Purpose. We describe a new dental implant with improved primary stability features. Study design. Lab bench test studies. Methods. We evaluated the new implant using static and flexion–compression fatigue tests with compression loads, 35 Ncm tightening torque, displacement control, 0.01 mm/s actuator movement speed, and 9–10 Hz load application frequency, obtaining a cyclic load diagram. We applied variable cyclic loadings of prede…

Searches for lepton number violating $K^+$ decays

2019

The NA62 experiment at CERN reports a search for the lepton number violating decays K+ -> pi(-)e(+)e(+) and K+ -> pi(-)mu(+)mu(+) using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of 2.2 x 10(-10) and 4.2 x 10(-11) are obtained, respectively, at 90% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively.