Co-reporter:Shi Peng, Qiang Zheng, Xin Zhang, Linghui Dai, Jingxian Zhu, Yanbin Pi, Xiaoqing Hu, Wenqing Cheng, Chunyan Zhou, Yinlin Sha, and Yingfang Ao
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 13) pp:6089
Publication Date(Web):May 28, 2013
DOI:10.1021/am400854z
A disintegrin and metalloproteinase with thrombospondin motif-4 (ADAMTS-4) plays a pivotal role in degrading aggrecan, which is an early event in cartilage degrading joint diseases such as osteoarthritis (OA). Detection of ADAMTS-4 activity could provide useful clinical information for early diagnosis of such diseases and disease-modifying therapy. Therefore, we developed a ADAMTS-4 detective fluorescent turn-on AuNP probe (ADAMTS-4-D-Au probe) by conjugating gold nanoparticles with a FITC-modified ADAMTS-4-specific peptide (DVQEFRGVTAVIR). When the ADAMTS-4-D-Au probe was incubated with ADAMTS-4, the fluorescence recovered and fluorescence intensity markedly increased in proportion to concentrations of ADAMTS-4 and the probe. A nearly 3-fold increase in fluorescent intensity in response to only 3.9 pM of ADAMTS-4 was detected, whereas almost no fluorescence recovery was observed when the probe was incubated with matrix metalloproteinase (MMP)-1, -3, and -13. These results indicate a relative high sensitivity and specificity of the probe. Moreover, ADAMTS-4-D-Au probe was used to detect ADAMTS-4 activity in synovial fluid from 11 knee surgery patients. A substantial increase in fluorescent intensity was observed in the acute joint injury group as compared to the chronic joint injury and end-stage OA groups, indicating that this simple and low-cost sensing system might serve as a new detection method for ADAMTS-4 activity in biological samples and in screens for inhibitors for ADAMTS-4-related joint diseases. Additionally, this probe could be a potential biomarker for early diagnosis of cartilage-degrading joint diseases.Keywords: ADAMTS-4; fluorescent probe; gold nanoparticles; osteoarthritis; synovial fluid;
Co-reporter:Yang Yang, Min Yu, Ting-Ting Yan, Zhi-Hui Zhao, Yin-Lin Sha, Zhong-Jun Li
Bioorganic & Medicinal Chemistry 2010 Volume 18(Issue 14) pp:5234-5240
Publication Date(Web):15 July 2010
DOI:10.1016/j.bmc.2010.05.046
We have previously reported a facile and convenient method for the preparation of a new type of lactose-CdSeS/ZnS quantum dots conjugates (Lac-QDs) that exhibit biocompatibility, noncytotoxicity and specificity to leukocytes. In order to further study the carbohydrate–protein interactions, a series of Lac-QDs with different lactose densities and a PEGylated (n = 3) lactose-QDs conjugate (LacPEG-QDs) with more flexible sugar ligands were prepared. The amount of the sugar molecules on QDs can be determined by NMR, which was in agreement with the results from TGA determination. The formula of the conjugates was determined with ICP-OES. The interactions between the conjugated QDs and the PNA protein were measured using SPR, which revealed that higher lactose density favored binding affinity under the same concentration, and Lac-QDs exhibit higher affinity than LacPEG-QDs. We further used a solid phase assay to assess the anti-adhesion activity of Lac-QDs and LacPEG-QDs on the cell level. The results showed that Lac-QDs had stronger activity in preventing THP1 from adhering to HUVEC than LacPEG-QDs, which was consistent with the SPR results. We reasoned that decrease in the conformational entropy induced by appropriate restriction of sugar flexibility could enhance the binding affinity of glyco-QDs, which implies that entropy change may be the main contributor to the interaction between high valent glyco-QDs and protein. The fabrication of lactose on QDs provides a fluorescent multivalent carbohydrate probe that can be used as mimics of glycoprotein for the study of carbohydrate–protein interactions and cell imaging.
Co-reporter:Jian Zhong, Chunhui Yang, Wenfu Zheng, Lixin Huang, Yuankai Hong, Lijun Wang, Yinlin Sha
Colloids and Surfaces B: Biointerfaces 2010 Volume 77(Issue 1) pp:40-46
Publication Date(Web):1 May 2010
DOI:10.1016/j.colsurfb.2010.01.001
In this work, we investigated the interactions of PrP106-126 amide with 1-palmitoyl-2-oleoyl-3-phosphocholine (POPC) and POPC/bovine brain sphingomyelin (BSM) membranes in the presence of calcium ions by in situ time-lapse atomic force microscopy (AFM) and circular dichroism (CD). The CD results show that Ca2+ has no obvious effects on the random coil conformation of PrP106-126 amide. The tapping mode AFM results demonstrate that electrostatic interaction decreases the measured heights of supported lipid bilayers (SLBs) in HBS–Ca2+ solution. Electrostatic interaction analysis also can be used to determine the applied force in liquid tapping mode AFM. The interactions of PrP106-126 amide with membranes by AFM demonstrate the following: (i) Ca2+ inhibits the interaction of PrP106-126 amide with POPC lipid and (ii) the co-interaction between Ca2+ and BSM increases the poration ability of PrP106-126 amide. These results imply that the main role of Ca2+ in the interactions of PrP106-126 amide with membranes is changing the surface properties of the membranes.
Co-reporter:Min Yu, Yang Yang, Rongcheng Han, Qiang Zheng, Lijun Wang, Yuankai Hong, Zhongjun Li and Yinlin Sha
Langmuir 2010 Volume 26(Issue 11) pp:8534-8539
Publication Date(Web):February 1, 2010
DOI:10.1021/la904488w
Oligosaccharides play crucial roles in many biorecognition processes by the so-called “cluster glycosidic effect”. We here report a facile synthesis of lactose-CdSeS/ZnS quantum dot conjugate (Lac-QDs) by use of 1-thiol-β-d-lactose via ligand exchange, which exhibits significantly high affinity and specificity to leukocytes in contrast to the monovalent lactose. Structural analyses indicate that there are about 132 lactosyl molecules assembled on single QDs and the hydrodynamic diameter is small, close to 8.2 nm. Further, Lac-QDs display good fluorescence and physicochemical stability in physiological conditions, as well as extremely low cytotoxicity. These properties facilitate the use of Lac-QDs in fluorescent labeling of live leukocytes.
Co-reporter:Rongcheng Han, Min Yu, Qiang Zheng, Lijun Wang, Yuankai Hong and Yinlin Sha
Langmuir 2009 Volume 25(Issue 20) pp:12250-12255
Publication Date(Web):July 13, 2009
DOI:10.1021/la9016596
In recent years, silica coating has been extensively investigated to fabricate the biocompatible interface of quantum dots (QDs) for biomedical applications. We here describe a facile and efficient method of synthesizing high-quality silica-coated CdSeS QDs (CdSeS QD/SiO2), where an immediate photoluminescence-favorable microenvironment is first created by assembling amphiphilic molecules around the CdSeS core, and a thin silica shell is further introduced to protect this hydrophobic interlayer. The prepared CdSeS QD/SiO2 exhibits excellent properties such as good water solubility, low cytotoxicity, and high quantum yield (QY, up to 0.49) as well as the resistance of photobleaching in aqueous solution. Also, the CdSeS QD/SiO2 nanoparticles homogeneously comprise single CdSeS cores and hold a comparatively small size up to about 11 nm in diameter. Particularly, this method leads to a significant increase in QY as compared to the uncoated CdSeS QDs (∼109% of the initial QY), though only thin silica shells formed in the CdSeS QD/SiO2 structure. By coupling with folic acids, the CdSeS QD/SiO2 conjugates were successfully used for tumor cell labeling. Our results demonstrated a robust hydrophobic QDs-based approach for preparing highly photoluminescent, biocompatible QD/SiO2 through creation of a stable hydrophobic interlayer surrounding the QD cores, which could be also suitable for silica coating of other kinds of hydrophobic nanoparticles.
Co-reporter:Lan Zhang, Jian Zhong, Lixin Huang, Lijun Wang, Yuankai Hong and Yinlin Sha
The Journal of Physical Chemistry B 2008 Volume 112(Issue 30) pp:8950-8954
Publication Date(Web):July 2, 2008
DOI:10.1021/jp802424h
Peptide self-assembly on substrates is currently an intensively studied topic that provides a promising strategy for fabrication of soft materials and is also important for revealing the surface chemistry of amyloidogenic proteins that aggregate on cell membranes. We investigated the fibrogenesis of a β-sheet forming peptide Aβ26−35 on supported lipid bilayers (SLBs) by in situ atomic force microscopy (AFM), circular dichroism (CD), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results show that the Aβ26−35 nanofilaments’ growth is oriented to a specific direction and formed a highly ordered, large-scale, parallel-oriented surface pattern on membranes. The parallel-oriented fibrogenesis of Aβ26−35 was able to occur on different lipid membranes rather than on solid substrates. It implies that the parallel-oriented fibrogenesis was associated with the distinct properties of lipid membranes, such as the fluid nature of lipid molecules on membranes. The membrane fluidity may allow the peptide assemblies to float at the water−membrane interface and easily orient to an energetically favorable state. These results provide an insight into the surface chemistry of peptide self-assembly on lipid membranes and highlight a possible way to fabricate supramolecular architectures on the surface of soft materials.
Co-reporter:Chong Wang;Lixin Huang;Lijun Wang;Yuankai Hong;Yinlin Sha
Biopolymers 2007 Volume 86(Issue 1) pp:
Publication Date(Web):10 JAN 2007
DOI:10.1002/bip.20681
Fabricating various nanostructures based on the self-assembly of diverse biological molecules is now of great interest to the field of bionanotechnology. In this study, we report a de novo designed peptide (T1) with a preferential β-hairpin forming property that can spontaneously assemble into nanofibrils in ultrapure water. The nanofibrils assembled by T1 could grow up to tens of microns in length with a left-handed helical twist and an average height of 4.9 ± 0.9 nm. Moreover, protofilaments and nucleus structures both with a similar height of 1.4 ± 0.2 nm were observed during fibrilization as well as via sonication of the mature nanofibrils. A typical conformational transition from random coil to β-structure was observed in association with the fibrilization. Molecular modeling of T1 assemblies displayed that the β-hairpin molecules organize in a parallel fashion in which the β-strands align in an antiparallel fashion and each adjoining β-strand runs left-handed twist at about 2.9° with respect to the one located before it along the fibrillar axis. It also revealed that the maximum thickness of the assembly intermediate, the helical tape structure, is about 1.4 nm and four tapes can further assemble into a fibril with a diameter of about 4.1 nm. Taken together the results obtained by AFM, CD, and molecular modeling, T1 fibrilization probably undergoes a hierarchy approach, in which the aromatic stacking and the electrostatic interactions between the assembled structures are most likely the two major factors directing the one-dimensional self-assembly. Based on these studies, we propose T1 can be used as a model peptide to investigate the β-sheet based self-assembly process and could be a potential bioorganic template to develop functional materials. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 23–31, 2007.
This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Co-reporter:Jian Zhong, Wenfu Zheng, Lixin Huang, Yuankai Hong, Lijun Wang, Yang Qiu, Yinlin Sha
Biochimica et Biophysica Acta (BBA) - Biomembranes (June 2007) Volume 1768(Issue 6) pp:
Publication Date(Web):June 2007
DOI:10.1016/j.bbamem.2007.03.003
A major hallmark of prion diseases is the cerebral amyloid accumulation of the pathogenic PrPSc, an abnormally misfolded, protease-resistant, and β-sheet rich protein. PrP106–126 is the key domain responsible for the conformational conversion and aggregation of PrP. It shares important physicochemical characteristics with PrPSc and presents similar neurotoxicity as PrPSc. By combination of fluorescence polarization, dye release assay and in situ time-lapse atomic force microscopy (AFM), we investigated the PrP106–126 amide interacting with the large unilamellar vesicles (LUVs) and the supported lipid bilayers (SLBs). The results suggest that the interactions involve a poration-mediated process: firstly, the peptide binding results in the formation of pores in the membranes, which penetrate only half of the membranes; subsequently, PrP106–126 amide undergoes the poration-mediated diffusion in the SLBs, represented by the formation and expansion of the flat high-rise domains (FHDs). The possible mechanisms of the interactions between PrP106–126 amide and lipid membranes are proposed based on our observations.
Co-reporter:Jian Zhong, Chunhui Yang, Wenfu Zheng, Lixin Huang, Yuankai Hong, Lijun Wang, Yinlin Sha
Biophysical Journal (3 June 2009) Volume 96(Issue 11) pp:
Publication Date(Web):3 June 2009
DOI:10.1016/j.bpj.2009.01.036
Lipid rafts are specialized liquid-ordered (Lo) phases of the cell membrane that are enriched in sphingolipids and cholesterol (Chl), and surrounded by a liquid-disordered (Ld) phase enriched in glycerophospholipids. Lipid rafts are involved in the generation of pathological forms of proteins that are associated with neurodegenerative diseases. To investigate the effects of lipid composition and phase on the generation of pathological forms of proteins, we constructed an Ld-gel phase-separated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/sphingomyelin (from bovine brain (BSM))-supported lipid bilayer (SLB) and an Ld-Lo phase-separated POPC/BSM/Chl SLB. We used in situ time-lapse atomic force microscopy to study the interactions between these SLBs and the prion peptide K106TNMKHMAGAAAAGAVVGGLG126 (PrP106–126) amide, numbered according to the human prion-peptide sequence. Our results show that: 1), with the presence of BSM in the Ld phase, the PrP106–126 amide induces fully penetrated porations in the Ld phase of POPC/BSM SLB and POPC/BSM/Chl SLB; 2), with the presence of both BSM and Chl in the Ld phase, the PrP106–126 amide induces the disintegration of the Ld phase of POPC/BSM/Chl SLB; and 3), with the presence of both BSM and Chl in the Lo phase, PrP106–126 amide induces membrane thinning in the Lo phase of POPC/BSM/Chl SLB. These results provide comprehensive insight into the process by which the PrP106–126 amide interacts with lipid membranes.
![(1,10-Phenanthroline)tris[4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionato]europium(III)](http://img.cochemist.com/ccimg/18000/17904-86-8.png)
![(1,10-Phenanthroline)tris[4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionato]europium(III)](http://img.cochemist.com/ccimg/18000/17904-86-8_b.png)
