keyword
MENU ▼
Read by QxMD icon Read
search

helix

keyword
https://www.readbyqxmd.com/read/28938749/the-testicular-transcriptome-associated-with-spermatogonia-differentiation-initiated-by-gonadotrophin-stimulation-in-the-juvenile-rhesus-monkey-macaca-mulatta
#1
Suresh Ramaswamy, William H Walker, Paula Aliberti, Rahil Sethi, Gary R Marshall, Alyxzandria Smith, Seyedmehdi Nourashrafeddin, Alicia Belgorosky, Uma R Chandran, Mark P Hedger, Tony M Plant
STUDY QUESTION: What is the genetic landscape within the testis of the juvenile rhesus monkey (Macaca mulatta) that underlies the decision of undifferentiated spermatogonia to commit to a pathway of differentiation when puberty is induced prematurely by exogenous LH and FSH stimulation? SUMMARY ANSWER: Forty-eight hours of gonadotrophin stimulation of the juvenile monkey testis resulted in the appearance of differentiating B spermatogonia and the emergence of 1362 up-regulated and 225 down-regulated testicular mRNAs encoding a complex network of proteins ranging from enzymes regulating Leydig cell steroidogenesis to membrane receptors, and from juxtacrine and paracrine factors to transcriptional factors governing spermatogonial stem cell fate...
October 1, 2017: Human Reproduction
https://www.readbyqxmd.com/read/28938653/overexpression-of-emt-inducing-transcription-factors-as-a-potential-poor-prognostic-factor-for-hepatocellular-carcinoma-in-asian-populations-a-meta-analysis
#2
Tao Wan, Tianwei Zhang, Xiaoying Si, Yanming Zhou
BACKGROUND AND OBJECTIVES: The clinical relevance of epithelial to mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) progression has been highlighted during the last decade. The zinc finger E-box binding homeobox (ZEB) family, the zinc-finger transcriptional repressor (SNAI) family, and the basic helix-loop-helix transcription factor (Twist) family, known as the prominent EMT-inducing transcription factors (EMT-TFs), played a crucial role in the process of EMT. Here, this meta-analysis aimed to evaluate the prognostic value of EMT-TFs high expression in patients with HCC after hepatectomy...
August 29, 2017: Oncotarget
https://www.readbyqxmd.com/read/28938518/antimicrobial-peptides-amps-the-quintessential-offense-and-defense-molecules-are-more-than-antimicrobials
#3
REVIEW
Seema Patel, Nadeem Akhtar
Antimicrobial peptides (AMPs) are cationic amphiphilic molecules with α-helix or β-sheet linear motifs and linear or cyclic configurations. For their role in 'defense and offense', they are present in all living organisms. AMPs are named so, as they inhibit a wide array of microbes by membrane pore formation and subsequent perturbation of mitochondrial membrane ionic balance. However, their functional repertoire is expanding with validated roles in cytotoxicity, wound healing, angiogenesis, apoptosis, and chemotaxis [1]...
September 18, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28937663/a-metallo-dna-nanowire-with-uninterrupted-one-dimensional-silver-array
#4
Jiro Kondo, Yoshinari Tada, Takenori Dairaku, Yoshikazu Hattori, Hisao Saneyoshi, Akira Ono, Yoshiyuki Tanaka
The double-helix structure of DNA, in which complementary strands reversibly hybridize to each other, not only explains how genetic information is stored and replicated, but also has proved very attractive for the development of nanomaterials. The discovery of metal-mediated base pairs has prompted the generation of short metal-DNA hybrid duplexes by a bottom-up approach. Here we describe a metallo-DNA nanowire-whose structure was solved by high-resolution X-ray crystallography-that consists of dodecamer duplexes held together by four different metal-mediated base pairs (the previously observed C-Ag-C, as well as G-Ag-G, G-Ag-C and T-Ag-T) and linked to each other through G overhangs involved in interduplex G-Ag-G...
October 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28937631/cellular-entry-of-the-diphtheria-toxin-does-not-require-the-formation-of-the-open-channel-state-by-its-translocation-domain
#5
Alexey S Ladokhin, Mauricio Vargas-Uribe, Mykola V Rodnin, Chiranjib Ghatak, Onkar Sharma
Cellular entry of diphtheria toxin is a multistage process involving receptor targeting, endocytosis, and translocation of the catalytic domain across the endosomal membrane into the cytosol. The latter is ensured by the translocation (T) domain of the toxin, capable of undergoing conformational refolding and membrane insertion in response to the acidification of the endosomal environment. While numerous now classical studies have demonstrated the formation of an ion-conducting conformation-the Open-Channel State (OCS)-as the final step of the refolding pathway, it remains unclear whether this channel constitutes an in vivo translocation pathway or is a byproduct of the translocation...
September 22, 2017: Toxins
https://www.readbyqxmd.com/read/28937163/effect-of-n-and-c-terminal-functional-groups-on-the-stability-of-collagen-triple-helices
#6
Jasmine Egli, Roman S Erdmann, Pascal J Schmidt, Helma Wennemers
The effect of charged versus neutral N- and C-termini on the stability of the collagen triple helix was examined. Thermal denaturation studies at different pH with collagen model peptides showed that an ammonium group at the N-terminus destabilizes the triple helix more than a carboxylate at the C-terminus. A neutral carboxylic acid stabilizes the triple helix more than an amido moiety at the C-terminus.
September 22, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28936502/effects-of-stereo-regularity-on-the-single-chain-mechanics-of-polylactic-acid-and-its-implications-on-the-physical-properties-of-bulk-materials
#7
Bo Cheng, Lu Qian, Hu-Jun Qian, Zhong-Yuan Lu, Shuxun Cui
The material properties of polylactic acid (PLA) are largely determined by its stereo-regularity (tacticity). To find out the origin at the molecular level, the single-chain mechanics of poly-l-lactic acid (PLLA) and poly-d,l-lactide (PDLLA) were comparatively investigated by single-molecule atomic force microscopy (AFM). At a low concentration, PLLA adopted a random-coil conformation in a good solvent. At a high concentration, however, the PLLA chain can be induced into a helix, which consumed additional energy during unfolding by further stretching...
September 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28935998/theory-of-amyloid-fibril-nucleation-from-folded-proteins
#8
Lingyun Zhang, Jeremy D Schmit
We present a theoretical model for the nucleation of amyloid fibrils. In our model we use helix-coil theory to describe the equilibrium between a soluble native state and an aggregation-prone unfolded state. We then extend the theory to include oligomers with β-sheet cores and calculate the free energy of these states using estimates for the energies of H-bonds, steric zipper interactions, and the conformational entropy cost of forming secondary structure. We find that states with fewer than ~10 β-strands are unstable relative to the dissociated state and three β-strands is the highest free energy state...
July 2017: Israel Journal of Chemistry
https://www.readbyqxmd.com/read/28935609/novel-insights-into-the-vancomycin-resistant-enterococcus-faecalis-v583-alkylhydroperoxide-reductase-subunit-f
#9
Yew Kwang Toh, Asha Manikkoth Balakrishna, Malathy Sony Subramanian Manimekalai, Boon Bin Chionh, Ramya Ramaswamy Chettiyan Seetharaman, Frank Eisenhaber, Birgit Eisenhaber, Gerhard Grüber
The ability of the vancomycin-resistant Enterococcus faecalis (V583) to restore redox homeostasis via antioxidant defense mechanism is of importance, and knowledge into this defense is essential to understand its antibiotic-resistance and survival in hosts. The flavoprotein disulfide reductase AhpR, composed of the subunits AhpC and AhpF, represents one such vital part. Circular permutation was found to be a feature of the AhpF protein family. E. faecalis (V583) AhpF (EfAhpF) appears to be a representative of a minor subclass of this family, the typically N-terminal two-fold thioredoxin-like domain (NTD_N/C) is located at the C-terminus, whereas the pyridine nucleotide-disulfide oxidoreductase domain is encoded in the N-terminal part of its sequence...
September 18, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28935372/structural-insights-into-the-dimer-tetramer-transition-of-fabi-from-bacillus-anthracis
#10
Hyun Tae Kim, Sulhee Kim, Byeong Kwan Na, Jiwoung Chung, Eunha Hwang, Kwang Yeon Hwang
Enoyl-ACP reductase (ENR, also known as FabI) has received considerable interest as an anti-bacterial target due to its essentiality in fatty acid synthesis. All the FabI structures reported to date, regardless of the organism, are composed of homo-tetramers, except for two structures: Bacillus cereus and Staphylococcus aureus FabI (bcFabI and saFabI, respectively), which have been reported as dimers. However, the reason for the existence of the dimeric form in these organisms and the biological meaning of dimeric and tetrameric forms of FabI are ambiguous...
September 18, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28935369/a-three-dimensional-model-of-rnase-p-in-the-hyperthermophilic-archaeon-pyrococcus-horikoshii-ot3
#11
Xuzhu Gao, Kosuke Oshima, Toshifumi Ueda, Takashi Nakashima, Makoto Kimura
Ribonuclease P (RNase P) is an endoribonuclease involved in maturation of the 5'-end of tRNA. We found previously that RNase P in the hyperthermophilic archaeon Pyrococcus horikoshii OT3 consists of a catalytic RNase P RNA (PhopRNA) and five protein cofactors designated PhoPop5, PhoRpp21, PhoRpp29, PhoRpp30, and PhoRpp38. The crystal structures of the five proteins have been determined, a three-dimensional (3-D) model of PhopRNA has been constructed, and biochemical data, including protein-RNA interaction sites, have become available...
September 18, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28935134/sites-contributing-to-trpa1-activation-by-the-anesthetic-propofol-identified-by-photoaffinity-labeling
#12
Kellie A Woll, Kenneth A Skinner, Eleonora Gianti, Natarajan V Bhanu, Benjamin A Garcia, Vincenzo Carnevale, Roderic G Eckenhoff, Rachelle Gaudet
In addition to inducing anesthesia, propofol activates a key component of the pain pathway, the transient receptor potential ankyrin 1 ion channel (TRPA1). Recent mutagenesis studies suggested a potential activation site within the transmembrane domain, near the A-967079 cavity. However, mutagenesis cannot distinguish between protein-based and ligand-based mechanisms, nor can this site explain the complex modulation by propofol. Thus more direct approaches are required to reveal potentially druggable binding sites...
September 19, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28934314/mode-of-action-of-plectasin-derived-peptides-against-gas-gangrene-associated-clostridium-perfringens-type-a
#13
Xueling Zheng, Xiumin Wang, Da Teng, Ruoyu Mao, Ya Hao, Na Yang, Lifen Zong, Jianhua Wang
NZ2114 and MP1102 are novel plectasin-derived peptides with potent activity against Gram-positive bacteria. The antibacterial characteristics and mechanism of NZ2114 and MP1102 against gas gangrene-associated Clostridium perfringens were studied for the first time. The minimal inhibitory concentration and minimal bactericidal concentration of NZ2114 and MP1102 against resistant C. perfringens type A strain CVCC 46 were 0.91 μM. Based on the fractional inhibitory concentration index (FICI) result, an additive or synergic effect was observed between NZ2114 (FICI = 0...
2017: PloS One
https://www.readbyqxmd.com/read/28934144/the-recognition-of-calmodulin-to-the-target-sequence-of-calcineurin-a-novel-binding-mode
#14
Chia-Lin Chyan, Deli Irene, Sin-Mao Lin
Calcineurin (CaN) is a Ca(2+)/calmodulin-dependent Ser/Thr protein phosphatase, which plays essential roles in many cellular and developmental processes. CaN comprises two subunits, a catalytic subunit (CaN-A, 60 kDa) and a regulatory subunit (CaN-B, 19 kDa). CaN-A tightly binds to CaN-B in the presence of minimal levels of Ca(2+), but the enzyme is inactive until activated by CaM. Upon binding to CaM, CaN then undergoes a conformational rearrangement, the auto inhibitory domain is displaced and thus allows for full activity...
September 21, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28933861/differential-effect-of-bilayer-thickness-on-sticholysin-activity
#15
Juan Palacios Ortega, Sara Garcia-Linares, Esperanza Rivera-de-Torre, Jose G Gavilanes, Alvaro Martinez-Del-Pozo, J Peter Slotte
In this study, we examined the influence of bilayer thickness on the activity of the actinoporin toxins sticholysin I and II (StnI and StnII) at 25 °C. Bilayer thickness was varied using di-monounsaturated phosphatidylcholine (PC) analogs (with 14:1, 16:1, 18:1, 20:1, and 22:1 acyl chains). In addition, N-14:0-sphingomyelin (SM) was always included because StnI and StnII are SM specific. Cholesterol was also incorporated as indicated. In cholesterol-free large unilamellar vesicles (LUV) the PC:SM molar ratio was 4:1, and when cholesterol was included, the complete molar ratio was 4:1:0...
September 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28933727/venomics-of-remipede-crustaceans-reveals-novel-peptide-diversity-and-illuminates-the-venom-s-biological-role
#16
Björn M von Reumont, Eivind A B Undheim, Robin-Tobias Jauss, Ronald A Jenner
We report the first integrated proteomic and transcriptomic investigation of a crustacean venom. Remipede crustaceans are the venomous sister group of hexapods, and the venom glands of the remipede Xibalbanus tulumensis express a considerably more complex cocktail of proteins and peptides than previously thought. We identified 32 venom protein families, including 13 novel peptide families that we name xibalbins, four of which lack similarities to any known structural class. Our proteomic data confirm the presence in the venom of 19 of the 32 families...
July 26, 2017: Toxins
https://www.readbyqxmd.com/read/28933693/structural-inhibition-of-dynamin-mediated-membrane-fission-by-endophilin
#17
Annika Hohendahl, Nathaniel Talledge, Valentina Galli, Peter S Shen, Frédéric Humbert, Pietro De Camilli, Adam Frost, Aurélien Roux
Dynamin, which mediates membrane fission during endocytosis, binds endophilin and other members of the Bin-Amphiphysin-Rvs (BAR) protein family. How endophilin influences endocytic membrane fission is still unclear. Here we show that dynamin-mediated membrane fission is potently inhibited in vitro when an excess of endophilin co-assembles with dynamin around membrane tubules. We further show by electron microscopy that endophilin intercalates between turns of the dynamin helix and impairs fission by preventing trans interactions between dynamin rungs that are thought to play critical roles in membrane constriction...
September 21, 2017: ELife
https://www.readbyqxmd.com/read/28933316/photo-activatable-akt-probe-a-new-tool-to-study-the-akt-dependent-physiopathology-of-cancer-cells
#18
Sanae Haga, Takeaki Ozawa, Naoki Morita, Mami Asano, Shigeki Jin, Michitaka Ozakia
Akt is commonly overexpressed and activated in cancer cells, and plays a pivotal role in cell survival, protection andchemo-resistance. Therefore, Akt is one of the target molecules in understanding characters of cancer cells and developing anti-cancer drugs. Here, we examined whether a newly developed photo-activatable Akt (PA-Akt) probe, based on a light-inducible protein interaction module of plant cryptochrome2 (CRY2) and cryptochrome-interacting basic-helix-loop-helix (CIB1), can regulate Akt-associated cell functions...
August 30, 2017: Oncology Research
https://www.readbyqxmd.com/read/28931605/structural-basis-for-clonal-diversity-of-the-human-t-cell-response-to-a-dominant-influenza-virus-epitope
#19
Xinbo Yang, Guobing Chen, Nan-Ping Weng, Roy A Mariuzza
Influenza A virus (IAV) causes an acute infection in humans that is normally eliminated by CD8+ cytotoxic T lymphocytes. Individuals expressing the major histocompatibility complex (MHC) class I molecule HLA-A2 produce cytotoxic T lymphocytes bearing T cell receptors (TCRs) that recognize the immunodominant IAV epitope GILGFVFTL (GIL). Most GIL-specific TCRs utilize α/β pairs encoded by the TRAV27/TRBV19 gene combination to recognize this relatively featureless peptide epitope (canonical TCRs). However, ~40% of GIL-specific TCRs express a wide variety of other TRAV/TRBV combinations (non-canonical TCRs)...
September 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28931059/whole-genome-sequencing-of-mutants-with-increased-resistance-against-the-two-peptide-bacteriocin-plantaricin-jk-reveals-a-putative-receptor-and-potential-docking-site
#20
Bie Ekblad, Jon Nissen-Meyer, Tom Kristensen
By whole-genome sequencing of resistant mutants, a putative receptor for plantaricin JK, a two-peptide bacteriocin produced by some Lactobacillus plantarum strains, was identified in Lactobacillus plantarum NCFB 965 and Weissella viridescens NCFB 1655. The receptors of the two species had 66% identical amino acid sequences and belong to the amino acid-polyamine-organocation (APC) transporter protein family. The resistant mutants contained point mutations in the protein-encoding gene resulting in either premature stop codons, leading to truncated versions of the protein, or single amino acid substitutions...
2017: PloS One
keyword
keyword
104706
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"