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121.
122.
Exposure to chronic drugs of abuse has been reported to produce significant changes in postsynaptic protein profile, dendritic spine morphology and synaptic transmission. In the present study we demonstrate alterations in dendritic spine morphology in the frontal cortex and nucleus accumbens of mice following chronic morphine treatment as well as during abstinence for two months. Such alterations were accompanied with significant upregulation of the postsynaptic protein Shank1 in synaptosomal enriched fractions. mRNA levels of Shank1 was also markedly increased during morphine treatment and during withdrawal. Studies of the different postsynaptic proteins at the protein and mRNA levels showed significant alterations in the morphine treated groups compared to that of saline treated controls. Taken together, these observations suggest that Shank1 may have an important role in the regulation of spine morphology induced by chronic morphine leading to addiction. 相似文献
123.
The fauna of oribatid mites in nests of the bar-bellied pitta, the blue-rumped pitta, and the whiterumped shama was studied at the Dong Nai Biosphere Reserve (South Vietnam). The data on the taxonomic composition, total number of species, dominant species, and their occurrence in nests are presented. 相似文献
124.
The biological affinities of semi-nomadic, early to mid-Holocene foragers of the mid-Ganga Plain, North India are undetermined, yet understanding their place in the population history of South Asia is important. Non-metric tooth trait frequencies are reported for three broadly contemporary, bio-culturally similar, and geographically proximate samples, collectively known as Mesolithic Lake Culture (MLC). The Arizona State University – Dental Anthropology System was used to score 43 tooth-trait combinations (23 maxillary; 21 mandibular). Non-metric trait frequencies are used to determine biological affinities of MLC to a global sample of living populations and to prehistoric and living groups of South Asia. 相似文献
125.
Arun P. Chandrasekharappa Sangamesh E. Badiger Pramod K. Dubey Sunil K. Panigrahi Sekhar Reddy V.V.V. Manukonda 《Bioorganic & medicinal chemistry letters》2013,23(9):2579-2584
A series of benzoxazole compounds containing oxamic acid were synthesized and screened for the PTP1B inhibition. Compound 31d showed best biochemical potency (Ki) of 6.7 μM. Structure–activity relationship were explained with the help of molecular modeling approach. 相似文献
126.
D. Rambabu Guttikonda Raja B. Yogi Sreenivas G.P.K. Seerapu K. Lalith Kumar Girdhar Singh Deora Devyani Haldar M.V.Basaveswara Rao Manojit Pal 《Bioorganic & medicinal chemistry letters》2013,23(5):1351-1357
Novel N-indolylmethyl substituted spiroindoline-3,2′-quinazolines were designed as potential inhibitiors of SIRT1. These compounds were synthesized in good yields by using Pd/C–Cu mediated coupling-cyclization strategy as a key step involving the reaction of 1-(prop-2-ynyl)-1′H-spiro[indoline-3,2′-quinazoline]-2,4′(3′H)-dione with 2-iodoanilides. Some of the compounds synthesized have shown encouraging inhibition of Sir 2 protein (a yeast homologue of mammalian SIRT1) in vitro and three of them showed dose dependent inhibition of Sir 2. The docking results suggested that the benzene ring of 1,2,3,4-tetrahydroquinazolin ring system of these molecules occupied the deep hydrophobic pocket of the protein and one of the NH along with the sulfonyl group participated in strong H-bonding interaction with the amino acid residues. 相似文献
127.
128.
The molecular integrity of the active site of phytases from fungi is critical for maintaining phytase function as efficient catalytic
machines. In this study, the molecular dynamics (MD) of two monomers of phytase B from Aspergillus niger, the disulfide intact
monomer (NAP) and a monomer with broken disulfide bonds (RAP), were simulated to explore the conformational basis of the
loss of catalytic activity when disulfide bonds are broken. The simulations indicated that the overall secondary and tertiary
structures of the two monomers were nearly identical but differed in some crucial secondary–structural elements in the vicinity of
the disulfide bonds and catalytic site. Disulfide bonds stabilize the β-sheet that contains residue Arg66 of the active site and
destabilize the α-helix that contains the catalytic residue Asp319. This stabilization and destabilization lead to changes in the shape
of the active–site pocket. Functionally important hydrogen bonds and atomic fluctuations in the catalytic pocket change during the
RAP simulation. None of the disulfide bonds are in or near the catalytic pocket but are most likely essential for maintaining the
native conformation of the catalytic site.
Abbreviations
PhyB - 2.5 pH acid phophatese from Aspergillus niger, NAP - disulphide intact monomer of Phytase B, RAP - disulphide reduced monomer of Phytase B, Rg - radius of gyration, RMSD - root mean square deviation, MD - molecular dynamics. 相似文献129.
130.
Ranajay Saha Surajit Rakshit Samir Kumar Pal 《Journal of molecular recognition : JMR》2013,26(11):568-577
Labelling of proteins with some extrinsic probe is unavoidable in molecular biology research. Particularly, spectroscopic studies in the optical region require fluorescence modification of native proteins by attaching polycyclic aromatic fluoroprobe with the proteins under investigation. Our present study aims to address the consequence of the attachment of a fluoroprobe at the protein surface in the molecular recognition of the protein by selectively small model receptor. A spectroscopic study involving apomyoglobin (Apo‐Mb) and cyclodextrin (CyD) of various cavity sizes as model globular protein and synthetic receptors, respectively, using steady‐state and picosecond‐resolved techniques, is detailed here. A study involving Förster resonance energy transfer, between intrinsic amino acid tryptophan (donor) and N, N‐dimethyl naphthalene moiety of the extrinsic dansyl probes at the surface of Apo‐Mb, precisely monitor changes in donor acceptor distance as a consequence of interaction of the protein with CyD having different cavity sizes (β and γ variety). Molecular modelling studies on the interaction of tryptophan and dansyl probe with β‐CyD is reported here and found to be consistent with the experimental observations. In order to investigate structural aspects of the interacting protein, we have used circular dichroism spectroscopy. Temperature‐dependent circular dichroism studies explore the change in the secondary structure of Apo‐Mb in association with CyD, before and after fluorescence modification of the protein. Overall, the study well exemplifies approaches to protein recognition by CyD as a synthetic receptor and offers a cautionary note on the use of hydrophobic fluorescent labels for proteins in biochemical studies involving recognition of molecules. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献