Assemblies of D-peptides for Targeting Cell Nucleolus

Author(s):  
Huaimin Wang ◽  
Zhaoqianqi Feng ◽  
Weiyi Tan ◽  
Bing Xu

<p>Selectively targeting cell nucleolus remains a challenge. Here we report the first case that D-peptides form membraneless molecular condensates with RNA for targeting cell nucleolus. A D-peptide derivative, enriched with lysine and hydrophobic residues, self-assembles to form nanoparticles, which enter cells through clathrin dependent endocytosis and mainly accumulate at cell nucleolus. Structural analogue of the D-peptide reveals that particle morphology of the assemblies, which depends on the side chain modification, favors the cellular uptake. Contrasting to those of the D-peptide, the assemblies of the corresponding L-enantiomer largely localize in cell lysosomes. Preliminary mechanism study suggests that the D-peptide nanoparticles interact with RNA to form membraneless condensates in the nucleolus, which further induces DNA damage and results in cell death. This work illustrates a new strategy for rationally designing supramolecular assemblies of D-peptides for targeting subcellular organelles.</p>

2019 ◽  
Author(s):  
Huaimin Wang ◽  
Zhaoqianqi Feng ◽  
Weiyi Tan ◽  
Bing Xu

<p>Selectively targeting cell nucleolus remains a challenge. Here we report the first case that D-peptides form membraneless molecular condensates with RNA for targeting cell nucleolus. A D-peptide derivative, enriched with lysine and hydrophobic residues, self-assembles to form nanoparticles, which enter cells through clathrin dependent endocytosis and mainly accumulate at cell nucleolus. Structural analogue of the D-peptide reveals that particle morphology of the assemblies, which depends on the side chain modification, favors the cellular uptake. Contrasting to those of the D-peptide, the assemblies of the corresponding L-enantiomer largely localize in cell lysosomes. Preliminary mechanism study suggests that the D-peptide nanoparticles interact with RNA to form membraneless condensates in the nucleolus, which further induces DNA damage and results in cell death. This work illustrates a new strategy for rationally designing supramolecular assemblies of D-peptides for targeting subcellular organelles.</p>


1999 ◽  
Vol 576 ◽  
Author(s):  
H. Kimura ◽  
K. Okita ◽  
M. Ichitani ◽  
M. Yonezawa ◽  
T. Sugimoto

ABSTRACTThe thermosetting mechanism of an organosilicon polymer containing carborane has been studied utilizing the 13and 29Si solid-state NMR method. The polymer having C≡C bonds in the main chain and CH═CH2, Si-H bonds, and carborane in the bulky side chain, shows a very highly thermal stability in air by curing. From 13C and 29Si NMR spectra of the polymer, it was found that the intermolecular cross-linking reactions of the polymer was due to (1) the diene reaction between Ph-C≡C and C≡C and (2) the addition reaction between side chain terminal and Ph-C≡C and between CH═CH2 and Si–H, and a very highly thermal stable structure is formed.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 790 ◽  
Author(s):  
Yuan Liang ◽  
Meili Sui ◽  
Maomao He ◽  
Zhiyong Wei ◽  
Wanxi Zhang

The intrinsic drawback of slow crystallization rate of poly(l-lactide) (PLLA) inevitably deteriorates its final properties of the molded articles. In this work, we proposed a new strategy towards poly(l-lactide) with enhanced crystallization rate by ring opening polymerization (ROP) of l-lactide (l-LA) catalyzed by biocompatible zinc salts of amino acids. For the first time we developed a one-pot facile method of zinc salts of amino acids acting dual roles of catalysis of l-LA polymerization and in situ nucleation of the as-prepared PLLA. Nine zinc salts of different amino acids, including three kinds of amino acids ligands (alanine, phenylalanine, and proline) with l/d-enantiomers and their equimolar racemic mixtures, were first prepared and tested as catalysts of l-LA polymerization. A partial racemization was observed for zinc salts of amino acids whereas no racemization was detected for the reference stannous octoate. The polymerization mechanism study showed that the interaction of zinc salts of amino acids and benzyl alcohol forms the actual initiator for l-LA polymerization. Isothermal crystallization kinetics analysis showed that the residual zinc salts of amino acids exhibited a significant nucleation effect on PLLA, evidenced by the promotion of the crystallization rate, depending on the amino acid ligand and its configuration. Meanwhile, the residual zinc salts of amino acids did not compromise the thermal stability of the pristine PLLA.


2012 ◽  
Vol 236-237 ◽  
pp. 731-735
Author(s):  
Chang Su ◽  
Ling Min Wang ◽  
Li Huan Xu ◽  
Jun Lei Liu ◽  
Fang Yang ◽  
...  

A copolymer of 4-(1H-pyrrol-1-yl)phenol (PLPY) and pyrrole ( P(PLPY-co-Py) )was synthesized. And the chemical structure and battery performance of the prepared materials were characterized comparably by 1H NMR, FT-IR spectra and galvanostatic charge-discharge testing using simulant lithium ion half-cell method, respectively. The results shows that the introduction of the phenol group to the pyrrole as a rigid side chain could prevent the polymer from agglomeration and optimize the particle morphology of the resulting polymers, all of which made it demonstrate a significantly improved specific capacity (73.9 mAh•g-1) compared with PPy (21.4 mAh•g-1)


2001 ◽  
Vol 79 (5-6) ◽  
pp. 1049-1057 ◽  
Author(s):  
Peter G Breed ◽  
James A Ramsden ◽  
John M Brown

Synthetic procedures for the preparation of two types of functional resin are described, both based on 2% cross-linked polystyrene with a high density (>60%) of side-chains and terminated by a primary alcohol. In the first case the C11 side-chain is linked to the polymer through a sulfide, and in the second an ether linkage is employed to incorporate a (CH2CH2O)4 unit. In both cases the resins have 13C NMR spectra that are informative in the chain terminus region without special operating conditions. Model intermolecular metathesis reactions were carried out on allylcarbamic acid tert-butyl ester and various alkenes with Grubbs' catalyst. On the basis of these experiments, gel-phase metathesis was successfully demonstrated between a polymer-bound allyl ether and simple symmetrical disubstituted alkenes, monitoring the extent of reaction by 13C NMR. These reactions did not go to completion even with recycling and some evidence for competing interchain metathesis is presented, based on the increased broadening and reduced mobility of the ensuing polymer.Key words: alkene metathesis, ruthenium, gel-phase, 13C NMR.


Structure ◽  
2007 ◽  
Vol 15 (3) ◽  
pp. 313-327 ◽  
Author(s):  
Andrew T. Namanja ◽  
Tao Peng ◽  
John S. Zintsmaster ◽  
Andrew C. Elson ◽  
Maria G. Shakour ◽  
...  

2015 ◽  
Vol 26 (8) ◽  
pp. 946-950 ◽  
Author(s):  
Jian Lu ◽  
Xiao-Bo Tian ◽  
Wei Huang

2019 ◽  
Vol 4 (4) ◽  
pp. 940-946 ◽  
Author(s):  
Dashen Dong ◽  
Qianqian Shi ◽  
Debabrata Sikdar ◽  
Yunmeng Zhao ◽  
Yiyi Liu ◽  
...  

Three distinct site-specific Ag-coated Au nanoarrows are achieved by simply controlling the CTAC concentration of growth solution and analyzed with electron microscopy as well as elemental mapping. The CTAC concentration-dependent, facet-specific passivation represents a new strategy to design particle morphology as well as composition.


1993 ◽  
Vol 48 (7) ◽  
pp. 1000-1008 ◽  
Author(s):  
Peter Link ◽  
Wolfgang Voelter

As part of our total synthesis of thymosin β4 an optimized synthesis of the C-terminal part of thymosin β4 is described. Side chain functional residues of the tridecapeptide are masked by tert-butyl and the α-amino residues are protected by Z groups. The fully protected peptide derivative was obtained by WSCI/HOBt coupling of three fragments representing the segments [31-35], [36-37] and [38-43].


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