scholarly journals Multicomponent peptide assemblies

2018 ◽  
Vol 47 (10) ◽  
pp. 3659-3720 ◽  
Author(s):  
Danielle M. Raymond ◽  
Bradley L. Nilsson
Keyword(s):  
Molecular Weight ◽  
Coiled Coil ◽  
Peptide Amphiphiles ◽  
Low Molecular Weight ◽  
Β Sheet

This review presents recent efforts in the development of multicomponent supramolecular peptide assemblies with a focus on multicomponent assemblies derived from β-sheet peptides, low molecular weight peptides, peptide amphiphiles, coiled coil peptides, collagen, and related systems.

scholarly journals A Novel Fluorescence Intensity Screening Assay Identifies New Low-Molecular-Weight Inhibitors of the gp41 Coiled-Coil Domain of Human Immunodeficiency Virus Type 1

2007 ◽  
Vol 51 (7) ◽  
pp. 2388-2395 ◽  
Author(s):  
Lifeng Cai ◽  
Miriam Gochin
Keyword(s):  
Molecular Weight ◽  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Coiled Coil ◽  
Heptad Repeat ◽  
Low Molecular Weight ◽  
Hydrophobic Pocket ◽  
Fusion Inhibitors ◽  
Immunodeficiency Virus

ABSTRACT A metallopeptide-based fluorescence assay has been designed for the detection of small-molecule inhibitors of human immunodeficiency virus type 1 gp41, the viral protein involved in membrane fusion. The assay involves two peptides representing the inner N-terminal-heptad-repeat (HR1) coiled coil and the outer C-terminal-heptad-repeat (HR2) helical domains of the gp41 six-helix bundle which forms prior to fusion. The two peptides span a hydrophobic pocket previously defined in the literature. The HR1 peptide is modified with a metal-ligated dye complex, which maintains structural integrity and permits association with a fluorophore-labeled HR2 peptide to be followed by fluorescence quenching. Compounds able to disrupt six-helix bundle formation can act as fusion inhibitors, and we show that they can be detected in the assay from an increase in the fluorescence that is correlated with the potency of the compound. Assay optimization and validation have resulted in a simple quantitative competitive inhibition assay for fusion inhibitors that bind in the hydrophobic pocket. The assay has an assay quality factor (Z′) of 0.88 and can rank order inhibitors at 10 μM concentration with Ki s in the range of 0.2 μM to 30 μM, an ideal range for drug discovery. Screening of a small peptidomimetic library has yielded three new low-molecular-weight gp41 inhibitors. In vitro syncytium inhibition assays confirmed that the compounds inhibited cell-cell fusion in the low micromolar range. These lead compounds provide a new molecular scaffold for the development of fusion inhibitors.

Is a cross-β-sheet structure of low molecular weight peptides necessary for the formation of fibrils and peptide hydrogels?

2018 ◽  
Vol 20 (27) ◽  
pp. 18158-18168 ◽  
Author(s):  
Niranjan V. Ilawe ◽  
Reinhard Schweitzer-Stenner ◽  
David DiGuiseppi ◽  
Bryan M. Wong
Keyword(s):  
Molecular Weight ◽  
Aqueous Solutions ◽  
Low Molecular Weight ◽  
Sheet Structure ◽  
Peptide Hydrogels ◽  
Β Sheet ◽  
Theory And Experiment

Using both theory and experiment, we identify two oligomer structures formed by tripeptides in aqueous solutions.

scholarly journals Energy landscapes of a mechanical prion and their implications for the molecular mechanism of long-term memory

2016 ◽  
Vol 113 (18) ◽  
pp. 5006-5011 ◽  
Author(s):  
Mingchen Chen ◽  
Weihua Zheng ◽  
Peter G. Wolynes
Keyword(s):  
Molecular Weight ◽  
Free Energy ◽  
Coiled Coil ◽  
Fiber Formation ◽  
Coarse Grained ◽  
Long Term Memory ◽  
Low Molecular Weight ◽  
Term Memory ◽  
Oligomeric Form

Aplysia cytoplasmic polyadenylation element binding (CPEB) protein, a translational regulator that recruits mRNAs and facilitates translation, has been shown to be a key component in the formation of long-term memory. Experimental data show that CPEB exists in at least a low-molecular weight coiled-coil oligomeric form and an amyloid fiber form involving the Q-rich domain (CPEB-Q). Using a coarse-grained energy landscape model, we predict the structures of the low-molecular weight oligomeric form and the dynamics of their transitions to the β-form. Up to the decamer, the oligomeric structures are predicted to be coiled coils. Free energy profiles confirm that the coiled coil is the most stable form for dimers and trimers. The structural transition from α to β is shown to be concentration dependent, with the transition barrier decreasing with increased concentration. We observe that a mechanical pulling force can facilitate the α-helix to β-sheet (α-to-β) transition by lowering the free energy barrier between the two forms. Interactome analysis of the CPEB protein suggests that its interactions with the cytoskeleton could provide the necessary mechanical force. We propose that, by exerting mechanical forces on CPEB oligomers, an active cytoskeleton can facilitate fiber formation. This mechanical catalysis makes possible a positive feedback loop that would help localize the formation of CPEB fibers to active synapse areas and mark those synapses for forming a long-term memory after the prion form is established. The functional role of the CPEB helical oligomers in this mechanism carries with it implications for targeting such species in neurodegenerative diseases.

Characterization of Putative a (1,3)-β-D-glucan (curdlan) Synthase for a Low Molecular Weight Curdlan Biosynthesis from Agrobacterium sp. M503

2013 ◽  
Vol 807-809 ◽  
pp. 2031-2034
Author(s):  
Yu Mei Li ◽  
Qiang Li ◽  
Sheng Han ◽  
Dong Xue Song ◽  
Yan Hong Qu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Random Coil ◽  
Low Molecular Weight ◽  
Base Pairs ◽  
Reading Frame ◽  
Coil Structure ◽  
Α Helix ◽  
Encoding Protein ◽  
Β Sheet

A β-(1,3)-D-glucan (curdlan) synthase gene for a low molecular weight curdlan biosynthesis, crdSAg, from Agrobacterium sp. M503 was cloned and its encoding protein was characterized by several online protein analysis softwares. The crdSAg consists of 1965-base-pairs Open Reading Frame (ORF) encoding a protein with molecular weight approximate 73.5 kDa, which contains the conserved domain of CESA-CelA_like belonging to glycosyltransferase family 2 (GT2). Moreover, CrdSAg was a membrane protein with seven hydrophobic transmembrance domains. The second structure analysis indicated it was composed of 43.12% α-helix, 17.89% β-sheet, and 38.99% random coil structure. These data will lay a foundation to clarify the biosynthesis mechanism of the low molecular weight curdlan.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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