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1. chinaXiv:201605.01734 [pdf]

Real-Time Monitoring Surface Chemistry-Dependent In Vivo Behaviors of Protein Nanocages via Encapsulating an NIR-II Ag2S Quantum Dot

Li, Chunyan; Zhang, Yejun; Wang, Qiangbin; Li, Feng; Zhang, Wenjing; Zhang, Xian-En
Subjects: Biology >> Biophysics

Protein nanocages (PNCs) have been recognized as a promising platform for nanomedicine innovation. Real-time in vivo tracking of PNCs can provide critically important information for the development of PNC-based diagnostics and therapeutics. Here we demonstrate a general strategy for monitoring the behaviors of PNCs in vivo by encapsulating a Ag2S quantum dot (QD) with fluorescence in the second near-infrared window (NIR-II, 1000-1700 nm) inside the PNC, using simian virus 40 (SV40) PNC (PNCSV40) as a model. Benefiting from the high spatiotemporal resolution and deep tissue penetration of NIR-II fluorescence imaging, the dynamic distribution of the PNCSV40 in living mice was tracked in real time with high fidelity, and adopting the PEGylation strategy, surface chemistry-dependent in vivo behaviors of PNCSV40 were clearly revealed. This study represents the first evidence of real-time tracking of the intrinsic behaviors of PNCs in vivo without interference in PNC-host interactions by encapsulating nanoprobes inside. The as-described imaging strategy will facilitate the study of interactions between exogenously introduced PNCs and host body and prompt the development of future protein-based drugs, sensors, and high-efficacy targeted delivery systems.

submitted time 2016-05-15 Hits3721Downloads1706 Comment 0

2. chinaXiv:201605.01496 [pdf]

Relaxant Action of Plumula Nelumbinis Extract on Mouse Airway Smooth Muscle

Tan, Li; Chen, Weiwei; Wei, Ming-Yu; Shen, Jinhua; Yu, Meng-Fei; Liu, Qing-Hua; Tan, Li; Chen, Weiwei; Wei, Ming-Yu; Shen, Jinhua; Yu, Meng-Fei; Liu, Qing-Hua; Yang, Guangzhong; Guo, Donglin; Guo, Donglin; Qin, Gangjian; Ji, Guangju
Subjects: Biology >> Biophysics >> Integrative & Complementary Medicine

The traditional herb Plumula Nelumbinis is widely used in the world because it has many biological activities, such as anti-inflammation, antioxidant, antihypertension, and butyrylcholinesterase inhibition. However, the action of Plumula Nelumbinis on airway smooth muscle (ASM) relaxation has not been investigated. A chloroform extract of Plumula Nelumbinis (CEPN) was prepared, which completely inhibited precontraction induced by high K+ in a concentration-dependent manner in mouse tracheal rings, but it had no effect on resting tension. CEPN also blocked voltage-dependent L-type Ca2+ channel-(VDCC-) mediated currents. In addition, ACh-induced precontraction was also completely blocked by CEPN and partially inhibited by nifedipine or pyrazole 3. Besides, CEPN partially reduced ACh-activated nonselective cation channel (NSCC) currents. Taken together, our data demonstrate that CEPN blocked VDCC and NSCC to inhibit Ca2+ influx, resulting in relaxation of precontracted ASM. This finding indicates that CEPN would be a candidate of new potent bronchodilators.

submitted time 2016-05-12 Hits2033Downloads1277 Comment 0

3. chinaXiv:201605.01412 [pdf]

Protein disulfide-isomerase, a folding catalyst and a redox-regulated chaperone

Wang, Lei; Wang, Xi; Wang, Chih-chen
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Protein disulfide-isomerase (PIN) was the first protein-folding catalyst to be characterized, half a century ago. It plays critical roles in a variety of physiological events by displaying oxidoreductase and redox-regulated chaperone activities. This review provides a brief history of the identification of PDI as both an enzyme and a molecular chaperone and of the recent advances in studies on the structure and dynamics of PDI, the substrate binding and release, and the cooperation with its partners to catalyze oxidative protein folding and maintain ER redox homeostasis. In this review, we highlight the structural features of PDI, including the high interdomain flexibility, the multiple binding sites, the two synergic active sites, and the redox-dependent conformational changes. (C) 2015 Elsevier Inc. All rights reserved.

submitted time 2016-05-12 Hits1517Downloads1046 Comment 0

4. chinaXiv:201605.01246 [pdf]

Chromatin Assembly of Histone Variants

Zhou Ju-Jun; Feng Xiao-Li; Zhou Zheng; Zhou Ju-Jun
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Chromatin assembly in eukaryote is a well-organized process in which DNA and histone are hierarchically packaged into the nucleosome and chromatin. The assembly and disassembly of chromatin decode the genetic information stored within the chromatin. Histone variant and histone chaperone are major players in regulating the chromatin assembly and virtually involve in all DNA-based processes. In this review, we discuss the recent findings that provide insights into the assembly mechanism of histone variant H2A.Z and CENP-A, and highlight the important roleshistone chaperones play in this process.

submitted time 2016-05-11 Hits1651Downloads855 Comment 0

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