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Kaur Jaspreet Kumar Vikas Sharma Kartik Kaur Sawinder Gat Yogesh Goyal Ankit Tanwar Beenu 《International journal of peptide research and therapeutics》2020,26(1):33-41
International Journal of Peptide Research and Therapeutics - Bioactive peptides have been reported to exhibit opioid-like activity and are termed as opioid peptides. Either these are produced... 相似文献
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Eben Goodale Hari Sridhar Kathryn E. Sieving Priti Bangal Gabriel J. Colorado Z. Damien R. Farine Eckhard W. Heymann Harrison H. Jones Indrikis Krams Ari E. Martínez Flavia Montao‐Centellas Jenny Muoz Umesh Srinivasan Anne Theo Kartik Shanker 《Biological reviews of the Cambridge Philosophical Society》2020,95(4):889-910
Mixed‐species animal groups (MSGs) are widely acknowledged to increase predator avoidance and foraging efficiency, among other benefits, and thereby increase participants' fitness. Diversity in MSG composition ranges from two to 70 species of very similar or completely different phenotypes. Yet consistency in organization is also observable in that one or a few species usually have disproportionate importance for MSG formation and/or maintenance. We propose a two‐dimensional framework for understanding this diversity and consistency, concentrating on the types of interactions possible between two individuals, usually of different species. One axis represents the similarity of benefit types traded between the individuals, while the second axis expresses asymmetry in the relative amount of benefits/costs accrued. Considering benefit types, one extreme represents the case of single‐species groups wherein all individuals obtain the same supplementary, group‐size‐related benefits, and the other extreme comprises associations of very different, but complementary species (e.g. one partner creates access to food while the other provides vigilance). The relevance of social information and the matching of activities (e.g. speed of movement) are highest for relationships on the supplementary side of this axis, but so is competition; relationships between species will occur at points along this gradient where the benefits outweigh the costs. Considering benefit amounts given or received, extreme asymmetry occurs when one species is exclusively a benefit provider and the other a benefit user. Within this parameter space, some MSG systems are constrained to one kind of interaction, such as shoals of fish of similar species or leader–follower interactions in fish and other taxa. Other MSGs, such as terrestrial bird flocks, can simultaneously include a variety of supplementary and complementary interactions. We review the benefits that species obtain across the diversity of MSG types, and argue that the degree and nature of asymmetry between benefit providers and users should be measured and not just assumed. We then discuss evolutionary shifts in MSG types, focusing on drivers towards similarity in group composition, and selection on benefit providers to enhance the benefits they can receive from other species. Finally, we conclude by considering how individual and collective behaviour in MSGs may influence both the structure and processes of communities. 相似文献
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Carolyn J. Heckman Rachel Chandler Jacqueline D. Kloss Amy Benson Deborah Rooney Teja Munshi Susan D. Darlow Clifford Perlis Sharon L. Manne David W. Oslin 《Journal of visualized experiments : JoVE》2013,(75)
Ultraviolet radiation (UV) therapy is sometimes used as a treatment for various common skin conditions, including psoriasis, acne, and eczema. The dosage of UV light is prescribed according to an individual''s skin sensitivity. Thus, to establish the proper dosage of UV light to administer to a patient, the patient is sometimes screened to determine a minimal erythema dose (MED), which is the amount of UV radiation that will produce minimal erythema (sunburn or redness caused by engorgement of capillaries) of an individual''s skin within a few hours following exposure. This article describes how to conduct minimal erythema dose (MED) testing. There is currently no easy way to determine an appropriate UV dose for clinical or research purposes without conducting formal MED testing, requiring observation hours after testing, or informal trial and error testing with the risks of under- or over-dosing. However, some alternative methods are discussed. 相似文献
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Pasupuleti Santhosh Kumar Katari Venkatesh Gopal Sowjenya Lokanathan Srikanth Manne Mudhu Sunitha Uppu Venkateswara Prasad 《Journal of biomolecular structure & dynamics》2013,31(10):2094-2103
Distal renal tubular acidosis (dRTA) is an autosomal recessive syndrome results defect in either proximal tubule bicarbonate reabsorption or in distal tubule H+ secretion and is characterized by severe hyperchloraemic metabolic acidosis in childhood. dRTA is associated with functional variations in the ATP6V1B1 gene encoding β1 subunit of H+-ATPase, key membrane transporters for net acid excretion of α-intercalated cells of medullary collecting ducts. In the present study, a 13-year-old male patient suffering with nephropathy and sensorineural deafness was reported in the Department of Nephrology. We predicted improper functioning of ATP6V1B1 gene could be the reason for diseased condition. Therefore, exons 3, 4, and 7 contributing active site of ATP6V1B1 gene was amplified and sequenced (Accession numbers: KF571726, KM222653). The obtained sequences were BLAST searched against the wild type ATP6V1B1 gene which showed novel mutations c.307 A > G, c.308 C > A, c.310 C > G, c.704 T > C, c.705 G > T, c.709 A > G, c.710 A > G, c.714 G > A, c.716 C > A, c.717delC, c.722 C > G, c.728insG, c.741insT, c.753G > C. These mutations resulted in the expression of truncated protein terminating at Lys 209. The mutated ATP6V1B1structure superimposed with wild type showed extensive variations with RMSD 1.336 Å and could not bind to substrate ADP leading to non-functional ATPase. These results conclusively explain these mutations in ATP6V1B1 gene resulted in structural changes causing accumulation of H+ ions contributing to dRTA with sensorineural deafness. 相似文献
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Chen Chen Vengadesan Krishnan Kevin Macon Kartik Manne Sthanam V. L. Narayana Olaf Schneewind 《The Journal of biological chemistry》2013,288(41):29440-29452
Staphylococcus epidermidis, a commensal of humans, secretes Esp protease to prevent Staphylococcus aureus biofilm formation and colonization. Blocking S. aureus colonization may reduce the incidence of invasive infectious diseases; however, the mechanism whereby Esp disrupts biofilms is unknown. We show here that Esp cleaves autolysin (Atl)-derived murein hydrolases and prevents staphylococcal release of DNA, which serves as extracellular matrix in biofilms. The three-dimensional structure of Esp was revealed by x-ray crystallography and shown to be highly similar to that of S. aureus V8 (SspA). Both atl and sspA are necessary for biofilm formation, and purified SspA cleaves Atl-derived murein hydrolases. Thus, S. aureus biofilms are formed via the controlled secretion and proteolysis of autolysin, and this developmental program appears to be perturbed by the Esp protease of S. epidermidis. 相似文献
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David C. Kombo Terry A. Hauser Vladimir P. Grinevich Matthew S. Melvin Jon-Paul Strachan Serguei S. Sidach Joseph Chewning Nikolai Fedorov Kartik Tallapragada Scott R. Breining Craig H. Miller 《Bioorganic & medicinal chemistry letters》2013,23(5):1450-1455
We have carried out a pharmacological evaluation of arylmethylene quinuclidine derivatives interactions with human α3β4 nAChRs subtype, using cell-based receptor binding, calcium-influx, electrophysiological patch-clamp assays and molecular modeling techniques. We have found that the compounds bind competitively to the α3β4 receptor with micromolar affinities and some of the compounds behave as non-competitive antagonists (compounds 1, 2 and 3), displaying submicromolar IC50 values. These evidences suggest a mixed mode of action for these compounds, having interactions at the orthosteric site and more pronounced interactions at an allosteric site to block agonist effects. One of the compounds, 1-benzyl-3-(diphenylmethylene)-1-azoniabicyclo[2.2.2]octane chloride (compound 3), exhibited poorly reversible use-dependent block of α3β4 channels. We also found that removal of a phenyl group from compound 1 confers a partial agonism to the derived analog (compound 6). Introducing a hydrogen-bond acceptor into the 3-benzylidene quinuclidine derivative (compound 7) increases agonism potency at the α3β4 receptor subtype. Docking into the orthosteric binding site of a α3β4 protein structure derived by comparative modeling accurately predicted the experimentally-observed trend in binding affinity. Results supported the notion that binding requires a hydrogen bond formation between the ligand basic nitrogen and the backbone carbonyl oxygen atom of the conserved Trp-149. 相似文献
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Kartik S. Bane Simone Lepper Jessica Kehrer Julia M. Sattler Mirko Singer Miriam Reinig Dennis Klug Kirsten Heiss Jake Baum Ann-Kristin Mueller Friedrich Frischknecht 《PLoS pathogens》2016,12(7)
Parasites causing malaria need to migrate in order to penetrate tissue barriers and enter host cells. Here we show that the actin filament-binding protein coronin regulates gliding motility in Plasmodium berghei sporozoites, the highly motile forms of a rodent malaria-causing parasite transmitted by mosquitoes. Parasites lacking coronin show motility defects that impair colonization of the mosquito salivary glands but not migration in the skin, yet result in decreased transmission efficiency. In non-motile sporozoites low calcium concentrations mediate actin-independent coronin localization to the periphery. Engagement of extracellular ligands triggers an intracellular calcium release followed by the actin-dependent relocalization of coronin to the rear and initiation of motility. Mutational analysis and imaging suggest that coronin organizes actin filaments for productive motility. Using coronin-mCherry as a marker for the presence of actin filaments we found that protein kinase A contributes to actin filament disassembly. We finally speculate that calcium and cAMP-mediated signaling regulate a switch from rapid parasite motility to host cell invasion by differentially influencing actin dynamics. 相似文献
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