Partial Denaturation of Villin Headpiece upon Binding to a Carbon Nitride Polyaniline (C3N) Nanosheet

2020 ◽  
Vol 124 (35) ◽  
pp. 7557-7563
Author(s):  
Zonglin Gu ◽  
Jose Manuel Perez-Aguilar ◽  
Lijun Meng ◽  
Ruhong Zhou
Keyword(s):  
Carbon Nitride ◽  
Villin Headpiece ◽  
Partial Denaturation

scholarly journals Structural Consequences of the Villin Headpiece Interaction with a Carbon Nitride Polyaniline (C3N) Nanosheet

2020 ◽  
Author(s):  
Zonglin Gu ◽  
Jose Manuel Perez-Aguilar ◽  
Ruhong Zhou
Keyword(s):  
Interaction Energy ◽  
Protein C ◽  
Biomedical Applications ◽  
Carbon Nitride ◽  
Md Simulations ◽  
Limited Information ◽  
Villin Headpiece ◽  
Partial Denaturation ◽  
Living Tissues ◽  
Shed Light

ABSTRACTCarbon nitride polyaniline (C3N) nanosheets shared a similar structure with graphene and have been utilized in biomedical applications since its recent successful synthesis. However, limited information was known about the interaction of this next-generation nanomaterial with biomolecules, which might hamper its applications in living tissues. Here, by using all-atom molecular dynamics (MD) simulations, we investigated the interaction between a C3N nanosheet and the prototypical protein villin headpiece (HP35), in order to identify the mechanistic determinants of such interaction; this knowledge will provide guidelines about C3N’s biocompatibility. Our MD simulations revealed that the C3N-based nanomaterial caused the partial denaturation of HP35 once the protein was bound on its surface. That is, upon adsorption, we observed the loss of the protein’s interior hydrogen bonds and the native contacts, which were related with unwinding events in the protein’s helices. The protein/C3N nanosheet interacting process was dominated by vdW contributions to the energy and the stepwise changes observed in the values of this energy term suggested a gradual unfolding pattern of HP35 during the absorption event. Furthermore, we also found that the interaction energy showed a linear correlation with the native Q ratio of HP35, suggesting that the degree of HP35 unfolding was linearly time-dependent to the interaction energy. Our findings shed light on the underlying molecular mechanism of the potential consequences of C3N-based nanostructures to proteins, which might delineate the future applications of these nanomaterials in biomedicine.

Replication of Bacteriophage 186 DNA

1972 ◽  
Vol 30 ◽  
pp. 194-195
Author(s):  
Dhruba K. Chattoraj ◽  
Ross B. Inman
Keyword(s):  
Electron Microscopy ◽  
Dna Replication ◽  
Frame Of Reference ◽  
Dna Molecules ◽  
E Coli ◽  
Phage Dna ◽  
Partial Denaturation

Electron microscopy of replicating intermediates has been quite useful in understanding the mechanism of DNA replication in DNA molecules of bacteriophage, mitochondria and plasmids. The use of partial denaturation mapping has made the tool more powerful by providing a frame of reference by which the position of the replicating forks in bacteriophage DNA can be determined on the circular replicating molecules. This provided an easy means to find the origin and direction of replication in λ and P2 phage DNA molecules. DNA of temperate E. coli phage 186 was found to have an unique denaturation map and encouraged us to look into its mode of replication.

Preparation and characterization of thin films of carbon nitride

1995 ◽  
Vol 53 ◽  
pp. 104-105
Author(s):  
L. Wan ◽  
R. F. Egerton
Keyword(s):  
Carbon Nitride ◽  
Arc Discharge ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Reactive Sputtering ◽  
Vacuum Arc ◽  
Specimen Preparation ◽  
Bonding Structure ◽  
Electron Energy Loss

INTRODUCTION Recently, a new compound carbon nitride (CNx) has captured the attention of materials scientists, resulting from the prediction of a metastable crystal structure β-C3N4. Calculations showed that the mechanical properties of β-C3N4 are close to those of diamond. Various methods, including high pressure synthesis, ion beam deposition, chemical vapor deposition, plasma enhanced evaporation, and reactive sputtering, have been used in an attempt to make this compound. In this paper, we present the results of electron energy loss spectroscopy (EELS) analysis of composition and bonding structure of CNX films deposited by two different methods.SPECIMEN PREPARATION Specimens were prepared by arc-discharge evaporation and reactive sputtering. The apparatus for evaporation is similar to the traditional setup of vacuum arc-discharge evaporation, but working in a 0.05 torr ambient of nitrogen or ammonia. A bias was applied between the carbon source and the substrate in order to generate more ions and electrons and change their energy. During deposition, this bias causes a secondary discharge between the source and the substrate.

Dissolution and Performing Homogeneous Photocatalysis of Polymeric Carbon Nitride

2018 ◽  
Author(s):  
Chaofeng Huang ◽  
Jing Wen ◽  
Yanfei Shen ◽  
Fei He ◽  
Li Mi ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Carbon Nitride ◽  
Heterogeneous Catalysts ◽  
Methane Sulfonic Acid ◽  
Environment Friendly ◽  
The Poor ◽  
Catalytic Sites ◽  
Homogeneous Photocatalysis ◽  
Polymeric Carbon ◽  
First Time

<a></a><a>As a metal-free conjugated polymer, carbon nitride (CN) has attracted tremendous attention as heterogeneous (photo)catalysts. </a><a></a><a>By following prototype of enzymes, making all catalytic sites of accessible via homogeneous reactions is a promising approach toward maximizing CN activity, but hindered due to </a><a></a><a>the poor insolubility of CN</a>. Herein, we report the dissolution of CN in environment-friendly methane sulfonic acid and the homogeneous photocatalysis driven by CN for the first time with the activity boosted up to 10-times, comparing to the heterogeneous counterparts. Moreover, facile recycling and reusability, the <a>hallmark</a> of heterogeneous catalysts, were kept for the homogeneous CN photocatalyst via reversible precipitation using poor solvents. It opens new vista of CN in homogeneous catalysis and offers a successful example of polymeric catalysts in bridging gaps of homo/heterogeneous catalysis.

Infrared Response in a Polymeric Carbon Nitride Via an Upconversion Mechanism

2019 ◽  
Author(s):  
Zhengyuan Jin ◽  
Xiantao Jiang ◽  
Qitao Zhang ◽  
Shaolong Huang ◽  
Luhong Zhang ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
Upconversion Mechanism ◽  
Polymeric Carbon

Metal Doped-C3N4/Fe2O4: Efficient and Versatile Heterogenous Catalysts for Organic Transformations

2019 ◽  
Vol 23 (12) ◽  
pp. 1284-1306
Author(s):  
Vijai K. Rai ◽  
Fooleswar Verma ◽  
Suhasini Mahata ◽  
Smita R. Bhardiya ◽  
Manorama Singh ◽  
...  
Keyword(s):  
Ring Opening ◽  
Carbon Nitride ◽  
Addition Reaction ◽  
High Surface ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Organic Transformations ◽  
Reduction Reactions ◽  
Activation Reaction ◽  
Metal Doped

The polymeric graphitic carbon nitride (g-C3N4) has been one of the interesting earth abundant elements. Though g-C3N4 finds application as a photocatalyst, its photocatalytic behaviour is limited because of low efficiency, mainly due to rapid charge recombination. To overcome this problem, several strategies have been developed including doping of metal/non-metal in the cavity of g-C3N4. Moreover, the CoFe2O4 NPs have been used in many organic transformations because of its high surface area and easy separation due to its magnetic nature. This review describes the role of cobalt ferrite as magnetic nanoparticles and metal-doped carbon nitride as efficient heterogeneous catalysts for new carbon-carbon and carbon-hetero atom bond formation followed by heterocyclization. Reactions which involved new catalysts for selective activation of readily available substrates has been reported herein. Since nanoparticles enhance the reactivity of catalyst due to higher catalytic area, they have been employed in various reactions such as addition reaction, C-H activation reaction, coupling reaction, cyclo-addition reaction, multi-component reaction, ring-opening reaction, oxidation reaction and reduction reactions etc. The driving force for choosing this topic is based-on huge number of good publications including different types of spinels/metal doped-/graphitic carbon nitride reported in the literature and due to interest of synthetic community in recent years. This review certainly will represent the present status in organic transformation and for exploring further their catalytic efficiency to new organic transformations involving C-H activation reaction through coupling, cyclo-addition, multi-component, ring-opening, oxidation and reduction reactions.

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