Photoluminescence dynamics of copper nanoclusters synthesized by cellulase: role of the random-coil structure

RSC Advances ◽  
2016 ◽  
Vol 6 (60) ◽  
pp. 55539-55545 ◽  
Author(s):  
Akanksha Singh ◽  
Tripti Rai ◽  
Debashis Panda
Keyword(s):  
Green Emission ◽  
Luminescent Properties ◽  
Random Coil ◽  
Copper Nanoclusters ◽  
Coil Structure ◽  
Random Coil Structure ◽  
Directed Synthesis

Cellulase-directed synthesis of magic numbered Cu NCs with blue-, cyan-, and green emission from Cu12, Cu20, and Cu34, respectively is presented. The random coil structure of enzyme dictates the size and luminescent properties of Cu NCs.

scholarly journals Structure and dynamics of the RNAPII CTDsome with Rtt103

2017 ◽  
Vol 114 (42) ◽  
pp. 11133-11138 ◽  
Author(s):  
Olga Jasnovidova ◽  
Tomas Klumpler ◽  
Karel Kubicek ◽  
Sergei Kalynych ◽  
Pavel Plevka ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Coiled Coil ◽  
Random Coil ◽  
Sequence Complexity ◽  
Structure And Dynamics ◽  
Coiled Coil Domain ◽  
Transcription Termination Factor ◽  
Coil Structure ◽  
Random Coil Structure ◽  
Long Rod

RNA polymerase II contains a long C-terminal domain (CTD) that regulates interactions at the site of transcription. The CTD architecture remains poorly understood due to its low sequence complexity, dynamic phosphorylation patterns, and structural variability. We used integrative structural biology to visualize the architecture of the CTD in complex with Rtt103, a 3′-end RNA-processing and transcription termination factor. Rtt103 forms homodimers via its long coiled-coil domain and associates densely on the repetitive sequence of the phosphorylated CTD via its N-terminal CTD-interacting domain. The CTD–Rtt103 association opens the compact random coil structure of the CTD, leading to a beads-on-a-string topology in which the long rod-shaped Rtt103 dimers define the topological and mobility restraints of the entire assembly. These findings underpin the importance of the structural plasticity of the CTD, which is templated by a particular set of CTD-binding proteins.

N.M.R. studies on myelin basic protein. I. 13C spectra in aqueous solutions

1978 ◽  
Vol 31 (11) ◽  
pp. 2367 ◽  
Author(s):  
BE Chapman ◽  
WJ Moore
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Polypeptide Chain ◽  
Random Coil ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Native Protein ◽  
Denatured Protein ◽  
Coil Structure ◽  
Random Coil Structure

Carbon-13 n.m.r, spectra have been obtained for bovine myelin basic protein at pD 4.4 in D2O and in 6 M guanidine deuterochloride solutions. Chemical-shift differences between resonances from some amino acid residues are interpreted in terms of structured regions in the polypeptide chain of the native protein, whereas the denatured protein displays the spectrum expected for an essentially random coil. Measurements of T1 and n.O.e. provide quantitative data on the dynamics of the backbone and side-chain carbons, and give support to the conclusion that the native protein does not have a random-coil structure.

scholarly journals Microwave Pretreatment and Enzymolysis Optimization of the Lotus Seed Protein

2019 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Bi Gohi ◽  
Jinze Du ◽  
Hong-Yan Zeng ◽  
Xiao-ju Cao ◽  
Kai Zou
Keyword(s):  
Secondary Structure ◽  
Seed Protein ◽  
Random Coil ◽  
Degree Of Hydrolysis ◽  
High Power Microwave ◽  
Lotus Seed ◽  
Coil Structure ◽  
Random Coil Structure ◽  
Optimized Conditions ◽  
Power Microwave

Pretreatment with a microwave was conducted before enzymolysis and shown to enhance the enzymolysis, which changed the secondary structure of the lotus seed protein. Under high-power microwave irradiation, sub bonds of the protein were broken, causing disaggregation and unfolding of the secondary structure, namely a decrease in the intermolecular aggregate structure and increase in the random coil structure, making the protein bonds susceptible to papain in the enzymolysis. On the other hand, a response surface methodology (RSM) was launched to investigate the influence of the enzymolysis process variables on the DH (degree of hydrolysis). The statistical analysis revealed that the optimized conditions were a protein substrate concentration of 15 g/L, pH of 5.5, enzymolysis temperature of 57 °C, papain amount of 0.5 g/L, and enzymolysis time of 45 min, for which the predicted value of the DH was 35.64%. The results indicated that a microwave also had better potential for applications in the enzymolysis of foods.

scholarly journals The glycine locating at random coil of picornaviruses VP3 enhances viral pathogenicity by targeting p53 to promote apoptosis and autophagy

2019 ◽  
Author(s):  
Ruoqing Mao ◽  
Fan Yang ◽  
Dehui Sun ◽  
Xiaoli Zhou ◽  
Zixiang Zhu ◽  
...  
Keyword(s):  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Underlying Mechanism ◽  
Skin Lesions ◽  
Random Coil ◽  
Autophagy Induction ◽  
Coil Structure ◽  
Mouth Disease Virus ◽  
Random Coil Structure ◽  
Seneca Valley Virus

AbstractPicornaviruses, comprising important and widespread pathogens of humans and animals, have evolved to control apoptosis and autophagy for their replication and spread. However, the underlying mechanism of the association between apoptosis/autophage and viral pathogenicity remains unclear. In the present study, VP3 of picornaviruses was demonstrated to induce apoptosis and autophagy. Foot-and-mouth disease virus (FMDV), which served as a research model here, can strongly induce both apoptosis and autophagy in the skin lesions. By directly interacting with p53, FMDV-VP3 facilitates its phosphorylation and translocation, resulting in Bcl-2 family-mediated apoptosis and LC3-dependent autophagy. The single residue Gly129 of FMDV-VP3 plays a crucial role in apoptosis and autophagy induction and the interaction with p53. Consistently, the comparison of rescued FMDV with mutated Gly129 and parental virus showed that the Gly129 is indispensable for viral replication and pathogenicity. More importantly, the Gly129 locates at a bend region of random coil structure, the mutation of Gly to Ala remarkably shrunk the volume of viral cavity. Coincidentally, the Gly is conserved in the similarly location of other picornaviruses, including poliovirus (PV), enterovirus 71 (EV71), coxsackievirus (CV) and seneca valley virus (SVA). This study demonstrates that picornaviruses induce apoptosis and autophagy to facilitate its pathogenicity and the Gly is functional site, providing novel insights into picornavirus biology.

Conformation of Systemin, a Polypeptide Activator of Proteinase Inhibitor Synthesis in Plants

1999 ◽  
Vol 64 (3) ◽  
pp. 553-558 ◽  
Author(s):  
Piotr Mucha ◽  
Agnieszka Szyk ◽  
Piotr Rekowski ◽  
Gotfryd Kupryszewski ◽  
Genowefa Slósarek ◽  
...  
Keyword(s):  
Proteinase Inhibitor ◽  
Nmr Spectra ◽  
Solid Phase ◽  
Random Coil ◽  
Phase Method ◽  
Free Zone ◽  
Coil Structure ◽  
Random Coil Structure ◽  
Solid Phase Method ◽  
Β Sheet

An 18-amino acid polypeptide systemin was synthesized by the solid-phase method and its conformation was studied by circular dichroism spectroscopy. The peptide in solution is a mixture of random coil structure with β-sheet and β-turn motifs as has been previously suggested with NMR spectra. Free zone capillary electrophoresis analysis proved purity and chemical stability of systemin at different pH.

scholarly journals A New Strategy for the Preparation of Porous Silk Fibroin Scaffolds

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Zhang T ◽  
◽  
Xiong Q ◽  
Shan Y ◽  
Zhang F ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Relative Humidity ◽  
Pore Structure ◽  
Silk Fibroin ◽  
Silk Gland ◽  
Random Coil ◽  
Structure Control ◽  
Coil Structure ◽  
Random Coil Structure ◽  
New Strategy

In order to prepare Silk Fibroin (SF) scaffolds with excellent pore structure, the fresh SF solution was concentrated at relative humidity 55% and 25°C for 3 days. During the above process, SF micelles, existed in the fresh SF solution, aggregated into nanofilaments as concentration increased, and the nanofilament feature of SF were similar to that observed in silk gland. SF nanofilaments were easy to form SF scaffolds with porous and silk I structure, in contrary, SF micelles were liable for formation of SF scaffolds with lamellar and random coil structure. It suggested that the formation of SF nanofilaments is a critical step for pore and secondary structure control of lyophilized SF scaffolds.

scholarly journals The random-coil ‘C’ fragment of the dihydropyridine receptor II-III loop can activate or inhibit native skeletal ryanodine receptors

2003 ◽  
Vol 372 (2) ◽  
pp. 305-316 ◽  
Author(s):  
Claudia S. HAARMANN ◽  
Daniel GREEN ◽  
Marco G. CASAROTTO ◽  
Derek R. LAVER ◽  
Angela F. DULHUNTY
Keyword(s):  
Lipid Bilayers ◽  
Rate Constant ◽  
Ryanodine Receptors ◽  
Dihydropyridine Receptor ◽  
Random Coil ◽  
Dynamic Changes ◽  
Independent Manner ◽  
Loop Sequence ◽  
Coil Structure ◽  
Random Coil Structure

The actions of peptide C, corresponding to 724Glu–Pro760 of the II–III loop of the skeletal dihydropyridine receptor, on ryanodine receptor (RyR) channels incorporated into lipid bilayers with the native sarcoplasmic reticulum membrane show that the peptide is a high-affinity activator of native skeletal RyRs at cytoplasmic concentrations of 100 nM–10 μM. In addition, we found that peptide C inhibits RyRs in a voltage-independent manner when added for longer times or at higher concentrations (up to 150 μM). Peptide C had a random-coil structure indicating that it briefly assumes a variety of structures, some of which might activate and others which might inhibit RyRs. The results suggest that RyR activation and inhibition by peptide C arise from independent stochastic processes. A rate constant of 7.5×105 s−1·M−1 was obtained for activation and a lower estimate for the rate constant for inhibition of 5.9×103 s−1·M−1. The combined actions of peptide C and peptide A (II–III loop sequence 671Thr–Leu690) showed that peptide C prevented activation but not blockage of RyRs by peptide A. We suggest that the effects of peptide C indicate functional interactions between a part of the dihydropyridine receptor and the RyR. These interactions could reflect either dynamic changes that occur during excitation–contraction coupling or interactions between the proteins at rest.

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