A new strategy to fabricate multifunctional luminescent MOFs, extending their application range from pH sensing to amino acid information coding

2021 ◽  
Author(s):  
Wanpeng Ma ◽  
Haifeng Lu ◽  
Bing Yan
Keyword(s):  
Amino Acid ◽  
Ph Sensing ◽  
Information Coding ◽  
Application Range ◽  
New Strategy

scholarly journals Effect of Cellulose Nanocrystal Addition on the Physicochemical Properties of Hydroxypropyl Guar-Based Intelligent Films

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 242
Author(s):  
Yahui Meng ◽  
Yunfeng Cao ◽  
Kaifeng Xiong ◽  
Li Ma ◽  
Wenyuan Zhu ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Composite Films ◽  
Food Preservation ◽  
Ph Sensing ◽  
Functional Material ◽  
Intelligent Packaging ◽  
Application Range ◽  
Color Changes ◽  
Hydroxypropyl Guar ◽  
Food Freshness

As an important functional material in food industry, intelligent packaging films can bring great convenience for consumers in the field of food preservation and freshness detection. Herein, we fabricated pH-sensing films employing hydroxypropyl guar (HPG), 1-butyl-3-methylimidazolium chloride (BmimCl), and anthocyanin (Anth). Besides, the effects of adding cellulose nanocrystals (CNC) into the composite films upon the films’ structures and physicochemical properties are elucidated. The addition of CNC promoted more compact film structures. Moreover, CNC dramatically improved several properties of the pH-sensing films, including the distinguishability of their color changes, sensitivity to pH, permeability to oxygen and water vapor, solvent resistance, durability, and low-temperature resistance. These results expand the application range of pH-sensing films containing CNC in the fields of food freshness detection and intelligent packaging.

scholarly journals Chiroptical Sensing of Amino Acid Derivatives by Host–Guest Complexation with Cyclo[6]aramide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4064
Author(s):  
Xuebin Wang ◽  
Jiecheng Ji ◽  
Zejiang Liu ◽  
Yimin Cai ◽  
Jialiang Tang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Density Functional ◽  
Cd Spectroscopy ◽  
Functional Theory ◽  
Chirality Transfer ◽  
Supramolecular Chirality ◽  
New Strategy ◽  
Spectroscopy Studies ◽  
Effective Component ◽  
Acid Esters

A hydrogen-bonded (H-bonded) amide macrocycle was found to serve as an effective component in the host–guest assembly for a supramolecular chirality transfer process. Circular dichroism (CD) spectroscopy studies showed that the near-planar macrocycle could produce a CD response when combined with three of the twelve L-α-amino acid esters (all cryptochiral molecules) tested as possible guests. The host–guest complexation between the macrocycle and cationic guests was explored using NMR, revealing the presence of a strong affinity involving the multi-point recognition of guests. This was further corroborated by density functional theory (DFT) calculations. The present work proposes a new strategy for amplifying the CD signals of cryptochiral molecules by means of H-bonded macrocycle-based host–guest association, and is expected to be useful in designing supramolecular chiroptical sensing materials.

scholarly journals Identification of Key Amino Acid Residues Determining Product Specificity of 2,3-Oxidosqualene Cyclase in Siraitia grosvenorii

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 577 ◽  
Author(s):  
Jing Qiao ◽  
Jiushi Liu ◽  
Jingjing Liao ◽  
Zuliang Luo ◽  
Xiaojun Ma ◽  
...  
Keyword(s):  
Amino Acid ◽  
Site Directed Mutagenesis ◽  
Bioactive Molecules ◽  
Amino Acid Residues ◽  
Product Specificity ◽  
Oxidosqualene Cyclase ◽  
Siraitia Grosvenorii ◽  
Initial Substrate ◽  
New Strategy ◽  
Key Residues

Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during the initial substrate preorganization step, oxidosqualene cyclases (OSCs) are roughly segregated into a dammarenyl cation group that predominantly catalyzes triterpenoid precursor products and a protosteryl cation group which mostly generates sterol precursor products. The mechanism of conversion between two scaffolds is not well understood. Previously, we have characterized a promiscuous OSC from Siraitia grosvenorii (SgCS) that synthesizes a novel cucurbitane-type triterpene cucurbitadienol as its main product. By integration of homology modeling, molecular docking and site-directed mutagenesis, we discover that five key amino acid residues (Asp486, Cys487, Cys565, Tyr535, and His260) may be responsible for interconversions between chair–boat–chair and chair–chair–chair conformations. The discovery of euphol, dihydrolanosterol, dihydroxyeuphol and tirucallenol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into cucurbitane-type and lanostane-type skeletons, and provide a new strategy to identify key residues determining OSC specificity.

Amino acid formula as a new strategy for diagnosing cow´s milk allergy in infants: is it cost-effective?

2016 ◽  
pp. 1-21
Author(s):  
Mauro Batista de Morais ◽  
José Vicente Spolidoro ◽  
Mário César Vieira ◽  
Ary Lopes Cardoso ◽  
Otavio Clark ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cost Effective ◽  
Milk Allergy ◽  
New Strategy ◽  
Amino Acid Formula

ChemInform Abstract: A New Strategy for the Construction of α-Amino Acid Esters via Decarboxylation.

ChemInform ◽  
2013 ◽  
Vol 44 (48) ◽  
pp. no-no
Author(s):  
Jie Zhang ◽  
Jiewen Jiang ◽  
Yuling Li ◽  
Yun Zhao ◽  
Xiaobing Wan
Keyword(s):  
Amino Acid ◽  
Amino Acid Esters ◽  
New Strategy ◽  
Acid Esters

scholarly journals Nanotubes Functionalized with Lipids and Natural Amino Acid Dendrimers: A New Strategy to Create Nanomaterials for Delivering Systemic RNAi

2010 ◽  
Vol 21 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Joshua McCarroll ◽  
Huricha Baigude ◽  
Chao-Shun Yang ◽  
Tariq M. Rana
Keyword(s):  
Amino Acid ◽  
Natural Amino Acid ◽  
New Strategy ◽  
Systemic Rnai

The conformational restriction of synthetic peptides, including a malaria peptide, for use as immunogens

1989 ◽  
Vol 323 (1217) ◽  
pp. 565-572 ◽  
Keyword(s):  
Hydrogen Bond ◽  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Hydrogen Bonds ◽  
Synthetic Peptides ◽  
Synthetic Methods ◽  
Amide Hydrogen ◽  
Conformational Restriction ◽  
Conformationally Restricted ◽  
New Strategy

A new strategy is advanced for the conformational restriction of peptidyl immunogens. Our approach is to replace putative amide-amide hydrogen bonds with covalent hydrogen-bond mimics. Because on average every other amino acid in a protein engages in this bond, the syntheses of diversely shaped peptides can be contemplated. Synthetic methods for introducing a potential hydrogen-bond mimic into a peptide with α-helical potential is reported and the structural consequences are discussed. The replacement of the hydrogen bond with a chemical link will modify as well as shape the peptide. To explore the consequences of these changes, a potential synthetic vaccine for malaria, the repeating tetrapeptide Asn-Pro-Asn-Ala, was conformationally restricted. Antibodies to the shaped malarial peptide showed a strong cross reaction with Plasmodium falciparum sporozoites.

ChemInform Abstract: A New Strategy for the Synthesis of Optically Pure β-Fluoroalkyl β-Amino Acid Derivatives.

ChemInform ◽  
2009 ◽  
Vol 40 (26) ◽  
Author(s):  
Santos Fustero ◽  
Carlos del Pozo ◽  
Silvia Catalan ◽  
Jose Aleman ◽  
Alejandro Parra ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Derivatives ◽  
New Strategy ◽  
Optically Pure

New Insights from the Structure Function of the Catalytic Region of Human Platelet PDE3A: The Role of the Unique 44 Amino Acid Insert.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3937-3937
Author(s):  
Su-Hwi Hung ◽  
Wei Zhang ◽  
Jing Tao ◽  
Carolyn Kim ◽  
Rachel Noone ◽  
...  
Keyword(s):  
Amino Acid ◽  
Human Platelet ◽  
Antiplatelet Agents ◽  
Chronic Congestive Heart Failure ◽  
Affinity Label ◽  
Tryptic Digest ◽  
Flexible Loop ◽  
New Strategy ◽  
Binding Kinetic

Abstract Human platelet PDE3A degrades cAMP, the major intracellular inhibitor of platelet function, and thus potentiates platelet activation. PDE3A is irreversibly inactivated by the affinity label Sp-cAMPS-BDB. The inactivation is prevented by Sp-cAMPS indicating that the affinity label is targeted at the cAMP binding site. We now use Sp-cAMPS-BDB with the aim of identifying nonconserved amino acids in substrate binding. After incubating Sp-cAMPS-BDB with PDE3A followed by reduction with [3H]NaBH4, the incorporation was 1.1 mol/mol. HPLC analysis of the tryptic digest yielded a radioactive octapeptide T806YNVTDDK813 in the 44-amino acid insert of PDE3A. Molecular modeling of PDE3A based on the PDE3B structure suggests the insert is a flexible loop. Incorporation of Sp-cAMPS-BDB indicates loop interaction with the substrate. Since Sp-cAMPS-BDB reacts with the nucleophilic residues, Y807, D811 and D812 were each mutated to alanine. Sp-cAMPS-BDB inactivates D811A and D812A but not Y807A, suggesting Y807 is the residue modified by Sp-cAMPS-BDB. Y807A affects the Km but not kcat, suggesting its involvement in cAMP binding. Kinetic analyses of 11 loop mutants reveal that H782A, T810A, Y814A and C816S each affects the kcat but not Km, indicating that catalysis is modulated. We conclude that binding of cAMP to the flexible loop of platelet PDE3A induces a conformational change which allows interaction with essential catalytic residues. These findings provide a new strategy for developing antiplatelet agents to treat patients with reocclusion of coronary arteries who are resistant to aspirin or whose chronic congestive heart failure prevents utilizing cilostazol.

Sign in / Sign up

Export Citation Format

Share Document