- Negative ion fragmentations of disulfide-containing crosslinking reagents are competitive with aspartic acid side-chain-induced cleavages
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RATIONALE: It has been shown that the disulfide moiety in the chemical crosslinking reagent dithiobis(succinimidyl)propionate (DSP), which is similar in structure to the natural cystine disulfide, cleaves preferentially to the peptide backbone in the negative ion mode. However, the tandem mass (MS/MS) spectra of peptides in the negative ion mode are often dominated by products arising from low-energy, side-chain-induced processes, which may compete with any facile cross-linker fragmentations and complicate identification of chemical crosslinks in a complex mixture. METHODS: Two disulfide-containing crosslinking reagents similar to DSP, but with varying spacer arm lengths, were synthesized and the MS/MS spectra of several model peptides cross-linked with these reagents were investigated. Theoretical calculations were used to describe the energetics of the cross-linker fragmentations as well as several low-energy side-chain-induced fragmentations which compete with disulfide cleavages. RESULTS: Altering the spacer arm length of the cross-linker, such that there is one methylene group less than in DSP, results in a more facile cleavage process, whilst the opposite is true when a methylene group is added. Of the low-energy side-chain-induced fragmentations studied, only those from aspartic acid compete significantly with those of the cross-linker disulfide. CONCLUSIONS: Lowenergy cleavage processes from aspartic acid that compete with cross-linker fragmentations occur in the negative ion MS/MS spectra of the cross-linked peptides, irrespective of the spacer arm length. Other fragmentation pathways do not significantly interfere with low-energy disulfide cleavage, making the presence of additional product ions in the MS/MS spectrum diagnostic for the presence of aspartic acid. Copyright
- Calabrese, Antonio N.,Wang, Tianfang,Bowie, John H.,Pukala, Tara L.
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- Heavy metal-free 19F NMR probes for quantitative measurements of glutathione reductase activity using silica nanoparticles as a signal quencher
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For the quantitative assessment of the glutathione reductase (GR) activity with a 19F NMR spectroscopy, we developed the heavy metal-free probes based on silica nanoparticles modified with water-soluble perfluorinated dendrimers via the disulfide linkers. Before enzymatic reaction, the molecular rotation of the perfluorinated dendrimers is highly restricted, and the magnitude of 19F NMR signals from the perfluorinated dendrimers can be suppressed. By the reductive cleavage of the disulfide linkers with the reduced glutathione-mediated enzymatic reaction of GR, perfluorinated dendrimers can be released from the surfaces of the nanoparticles. Consequently, the 19F NMR signals of perfluorinated dendrimers were recovered. The enzymatic activity of GR was determined from the increase of the magnitude of 19F NMR signals. Finally, to demonstrate the feasibility of the probe in the presence of miscellaneous molecules under bio-mimetic conditions, the comparison study was executed with the cancer cell lysate. The value determined from our method showed a good agreement with that from the conventional method.
- Tanaka, Kazuo,Kitamura, Narufumi,Chujo, Yoshiki
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- Neuroprotective effect of gold nanoparticles composites in Parkinson's disease model
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Parkinson's disease (PD) is second most common neurodegenerative disorder worldwide. Although drugs and surgery can relieve the symptoms of PD, these therapies are incapable of fundamentally treating the disease. For PD patients, over-expression of α-synuclein (SNCA) leads to the death of dopaminergic neurons. This process can be prevented by suppressing SNCA over-expression through RNA interference. Here, we successfully synthesized gold nanoparticles (GNP) composites (CTS@GNP-pDNA-NGF) via the combination of electrostatic adsorption and photochemical immobilization, which could load plasmid DNA (pDNA) and target specific cell types. GNP was transfected into cells via endocytosis to inhibiting the apoptosis of PC12 cells and dopaminergic neurons. Simultaneously, GNP composites are also used in PD models in vivo, and it can successfully cross the blood-brain barrier by contents of GNP in the mice brain. In general, all the works demonstrated that GNP composites have good therapeutic effects for PD models in vitro and in vivo.
- Hu, Kaikai,Chen, Xiaohui,Chen, Wuya,Zhang, Lingkun,Li, Jian,Ye, Jialin,Zhang, Yuxiao,Zhang, Li,Li, Chu-Hua,Yin, Liang,Guan, Yan-Qing
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- Facile, template-free synthesis of stimuli-responsive polymer nanocapsules for targeted drug delivery
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(Figure Presented) Open Sesame! A synthetic approach to stimuli-responsive polymer nanocapsules has been developed. The reductively labile polymer nanocapsule allows for not only facile, noncovalent surface modification but also the release of encapsulated cargo in response to a predefined redox stimulus in an intracellular environment.
- Kim, Eunju,Kim, Dongwoo,Jung, Hyuntae,Lee, Jiyeong,Paul, Somak,Selvapalam, Narayanan,Yang, Yosep,Lim, Namseok,Park, Chan Gyung,Kim, Kimoon
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- Fabrication of highly stable glyco-gold nanoparticles and development of a glyco-gold nanoparticle-based oriented immobilized antibody microarray for lectin (GOAL) assay
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The design of high-affinity lectin ligands is critical for enhancing the inherently weak binding affinities of monomeric carbohydrates to their binding proteins. Glyco-gold nanoparticles (glyco-AuNPs) are promising multivalent glycan displays that can confer significantly improved functional affinity of glyco-AuNPs to proteins. Here, AuNPs are functionalized with several different carbohydrates to profile lectin affinities. We demonstrate that AuNPs functionalized with mixed thiolated ligands comprising glycan (70 mol%) and an amphiphilic linker (30 mol%) provide long-term stability in solutions containing high concentrations of salts and proteins, with no evidence of nonspecific protein adsorption. These highly stable glyco-AuNPs enable the detection of model plant lectins such as Concanavalin A, wheat germ agglutinin, and Ricinus communis Agglutinin 120, at subnanomolar and low picomolar levels through UV/Vis spectrophotometry and dynamic light scattering, respectively. Moreover, we develop in situ glyco-AuNPs-based agglutination on an oriented immobilized antibody microarray, which permits highly sensitive lectin sensing with the naked eye. In addition, this microarray is capable of detecting lectins presented individually, in other environmental settings, or in a mixture of samples. These results indicate that glyconanoparticles represent a versatile and highly sensitive method for detecting and probing the binding of glycan to proteins, with significant implications for the construction of a variety of platforms for the development of glyconanoparticle-based biosensors.
- Huang, Li-De,Adak, Avijit K.,Yu, Ching-Ching,Hsiao, Wei-Chen,Lin, Hong-Jyune,Chen, Mu-Lin,Lin, Chun-Cheng
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- DLL3-TARGETING MULTISPECIFIC ANTIGEN-BINDING MOLECULES AND USES THEREOF
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The disclosure provides multispecific antigen-binding molecules that comprise a first antigen-binding moiety and a second antigen-binding moiety, each of which is capable of binding to CD3 and CD137, but does not bind to CD3 and CD137 at the same time; and a third antigen-binding moiety that is capable of binding to DLL3, preferably human DLL3, which induce T-cell dependent cytotoxity more efficiently whilst circumventing adverse toxicity concerns or side effects that other multispecific antigen-binding molecules may have. The present invention provides multispecific antigen-binding molecules and pharmaceutical compositions that can treat various cancers, especially those associated with DLL3, by comprising the antigen-binding molecule as an active ingredient.
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- Efficient Light-Harvesting Systems with Tunable Emission through Controlled Precipitation in Confined Nanospace
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Light harvesting is a key step in photosynthesis but creation of synthetic light-harvesting systems (LHSs) with high efficiencies has been challenging. When donor and acceptor dyes with aggregation-induced emission were trapped within the interior of cross-linked reverse vesicles, LHSs were obtained readily through spontaneous hydrophobically driven aggregation of the dyes in water. Aggregation in the confined nanospace was critical to the energy transfer and the light-harvesting efficiency. The efficiency of the excitation energy transfer (EET) reached 95 % at a donor/acceptor ratio of 100:1 and the energy transfer was clearly visible even at a donor/acceptor ratio of 10 000:1. Multicolor emission was achieved simply by tuning the donor/acceptor feed ratio in the preparation and the quantum yield of white light emission from the system was 0.38, the highest reported for organic materials in water to date.
- Li, Chuanqi,Zhang, Jing,Zhang, Shiyong,Zhao, Yan
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supporting information
p. 1643 - 1647
(2019/01/04)
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- NON-HUMAN ANIMAL HAVING HUMAN CD3 GENE SUBSTITUTED FOR ENDOGENOUS CD3 GENE
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The present invention provides genetically modified non-human animals which are deficient in at least one or more types of CD3 genes selected from the group consisting of endogenous CD3ε, CD3δ, and CD3γ in its genome and functionally express at least one or more types of human CD3 genes selected from the group consisting of human CD3?, CD3δ, and CD3γ. In the genetically modified non-human animals of the present invention, mature T cell differentiation and production can take place, and immunocompetent cells including T cells can exert their functions. The genetically modified non-human animals of the present invention enable efficient evaluation and screening in the development of therapeutic agents and therapeutic methods that use human CD3-mediated targeted drugs.
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- For inhibiting neural cell apoptosis of gold nano-particle complexes and use thereof
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The invention provides a gold nanoparticle complex with an effect of inhibiting nerve cell apoptosis and an application thereof. The gold nanoparticle complex is prepared by the following steps: modifying thiolated chitosan (TCTS) onto the surface of gold nanoparticles, performing electrostatic adsorption on pDNA interfering alpha-synuclein synthesis, finally grafting a nerve growth factor by adopting a photo-grafting method, thereby obtaining the complex. The successfully synthesized gold nanoparticle complex acts on nerve cells, the cell apoptosis can be obviously inhibited by the complex, and the complex has an effect of inhibiting apoptosis of an in-vitro cell model for Parkinson's disease, is a method and novel drug for treating the Parkinson's disease occurring after operative treatment and chemotherapy and has high guiding significance for treating and researching the disease.
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Paragraph 0056-0058
(2018/01/19)
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- Synthesis method of 3,3'-dithiodipropionic acid bis(N-hydroxyl succinimide ester)
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The invention discloses a synthesis method of 3,3'-dithiodipropionic acid bis(N-hydroxyl succinimide ester). The synthesis method comprises the following steps: weighing 0.028 mol of 3,3-dithiodipropionic acid, 0.06 mol of N-hydroxyl succinimide, and 0.06 mol of EDC hydrochloride, placing the substances into a container, adding 40 mL of dichloromethane, stirring at a room temperature to gradually dissolving the solids, carrying out reactions for a whole night, filtering to obtain white solids, and drying the white solids through baking to obtain the product. The provided synthesis method has the advantages of high yield, good crystallization effect, and high purity, and the prepared 3,3'-dithiodipropionic acid bis(N-hydroxyl succinimide ester) can be used as a high purity sample for subsequent chemical and biological experiments.
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Paragraph 0021; 0022; 0023
(2016/11/14)
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- SITE SELECTIVE CONJUGATION OF AN OLIGONUCLEOTIDE CONJUGATE OR A SMALL MOLECULE TO A METAL BINDING PROTEIN
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The present invention relates to methods for site selective conjugation of an oligonucleotide conjugate to a metal binding protein comprising a metal binding site and for site selective conjugation of a small molecule conjugation compound (SMCoC) to an antibody comprising a metal binding site, metal binding protein conjugates obtainable by said methods, and uses of said metal binding protein conjugates.
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Page/Page column 42; 43
(2016/01/25)
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- Synthesis and characterization of a 'fluorous' (fluorinated alkyl) affinity reagent that labels primary amine groups in proteins/peptides
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Strong non-covalent interactions such as biotin-avidin affinity play critical roles in protein/peptide purification. A new type of 'fluorous' (fluorinated alkyl) affinity approach has gained popularity due especially to its low level of non-specific binding to proteins/peptides. We have developed a novel water-soluble fluorous labeling reagent that is reactive (via an active sulfo-N-hydroxylsuccinimidyl ester group) to primary amine groups in proteins/peptides. After fluorous affinity purification, the bulky fluorous tag moiety and the long oligoethylene glycol (OEG) spacer of this labeling reagent can be trimmed via the cleavage of an acid labile linker. Upon collision-induced dissociation, the labeled peptide ion yields a characteristic fragment that can be retrieved from the residual portion of the fluorous affinity tag, and this fragment ion can serve as a marker to indicate that the relevant peptide has been successfully labeled. As a proof of principle, the newly synthesized fluorous labeling reagent was evaluated for peptide/protein labeling ability in phosphate-buffered saline (PBS). Results show that both the aqueous environment protein/peptide labeling and the affinity enrichment/separation process were highly efficient.
- Qian, Jiang,Cole, Richard B.,Cai, Yang
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experimental part
p. 1 - 11
(2011/10/09)
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- Isotactic polyethylenimines induce formation of L-amino acids in transamination
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(Chemical Equation Presented) Isotactic polyethylenimines with (S)-benzyl side chains were synthesized from 4-(S)-4-benzyl-2-oxazolines. When α-keto acids were subjected to transamination in the presence of this polymer, and a pyridoxamine coenzyme modified with hydrophobic chains, enantioselectivity toward the natural isomer (L > D) was observed, followed by racemization of the amino acid products. However, the racemization did not occur when the coenzyme was covalently attached to the polymer.
- Bandyopadhyay, Subhajit,Zhou, Wenjun,Breslow, Ronald
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p. 1009 - 1012
(2007/10/03)
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- Substantially cell membrane impermeable compound and use thereof
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The present invention relates to a compound according to Formula (I): A-(L-Y)p, wherein A comprises at least one substantially cell-membrane impermeable pendant group; L comprises any suitable linker and/or spacer group; Y comprises at least one arsenoxide or arsenoxide equivalent; p is an integer from 1 to 10; and the sum total of carbon atoms in A and L together, is greater than 6.
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Page/Page column 44
(2008/06/13)
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- Parallel vs. anti-parallel orientation in a curdlan/oligo(dA) complex as estimated by a FRET technique
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We already found that β-1,3-glucan polysaccharides form polymeric complexes with certain polynucleotides, but the parallel vs. anti-parallel orientation in those complexes had remained unsolved. In this paper, this controversial problem has been discussed for curdlan/oligo(dA) complexes utilizing two different energy transfer techniques. The first system consists of a combination of fiuorescein-labeled curdlan and 3′-(or 5′-)tetramethyl-rhodamine (TAMRA)-labeled oligo(dA). The second system utilizes gold nanoparticles: that is, two curdlan chains were linked by a disulfide bond and after complexation with oligo(dA), the complex was immobilized on gold nanoparticles. In this system, TAMRA was attached to the 3′ (or 5′) end of oligo(dA) and the gold particle acted as a fluorescence quencher (energy acceptor). These experiments have led us to conclude that in the curdlan/oligo(dA) complex, parallel orientation is more favourable than anti-parallel orientation. These findings have enabled us to envision a clearer image for the complexation mode between ss-1,3-glucan polysaccharides and polynucleotides. The Royal Society of Chemistry 2005.
- Numata, Munenori,Koumoto, Kazuya,Mizu, Masami,Sakurai, Kazuo,Shinkal, Seiji
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p. 2255 - 2261
(2007/10/03)
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- Compound, dithiobis-(succinimidyl propionate)
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The present disclosure describes preparation of the novel compound, dithiobis-(succinimidyl propionate) represented by the following structure: EQU1 MW 404.42
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