Supramolecular assemblies of dinuclear alkynylplatinum(ii) terpyridine complexes with double-decker silsesquioxane nano-cores: the role of isomerism in constructing nano-structures

2018 ◽  
Vol 54 (33) ◽  
pp. 4128-4131 ◽  
Author(s):  
Ho-Leung Au-Yeung ◽  
Sammual Yu-Lut Leung ◽  
Vivian Wing-Wah Yam
Keyword(s):  
Supramolecular Assemblies ◽  
Nano Structures ◽  
Double Decker ◽  
Self Association

Isomerically pure DDSQ-functionalized platinum(ii) complexes have been isolated with self-association behaviours found to be closely related to their isomeric configurations.

Striking a balance: Role of supramolecular assemblies on the modulation of the chemical and mechanical contributions during Post-STI CMP cleaning

2021 ◽  
Vol 259 ◽  
pp. 124170
Author(s):  
Carolyn F. Graverson ◽  
Katherine M. Wortman-Otto ◽  
Abigail N. Linhart ◽  
Yasa Sampurno ◽  
Ara Philipossian ◽  
...  
Keyword(s):  
Supramolecular Assemblies

scholarly journals Role of Kaposi's Sarcoma-Associated Herpesvirus C-Terminal LANA Chromosome Binding in Episome Persistence

2009 ◽  
Vol 83 (9) ◽  
pp. 4326-4337 ◽  
Author(s):  
Brenna Kelley-Clarke ◽  
Erika De Leon-Vazquez ◽  
Katherine Slain ◽  
Andrew J. Barbera ◽  
Kenneth M. Kaye
Keyword(s):  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Chromosome Association ◽  
Mitotic Chromosomes ◽  
Dividing Cells ◽  
Kaposi's Sarcoma Associated Herpesvirus ◽  
Self Association ◽  
Kaposi’S Sarcoma Associated Herpesvirus ◽  
Chromosome Binding

ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV) LANA is an 1,162-amino-acid protein that tethers terminal repeat (TR) DNA to mitotic chromosomes to mediate episome persistence in dividing cells. C-terminal LANA self-associates to bind TR DNA. LANA contains independent N- and C-terminal chromosome binding regions. N-terminal LANA binds histones H2A/H2B to attach to chromosomes, and this binding is essential for episome persistence. We now investigate the role of C-terminal chromosome binding in LANA function. Alanine substitutions for LANA residues 1068LKK1070 and 1125SHP1127 severely impaired chromosome binding but did not reduce the other C-terminal LANA functions of self-association or DNA binding. The 1068LKK1070 and 1125SHP1127 substitutions did not reduce LANA's inhibition of RB1-induced growth arrest, transactivation of the CDK2 promoter, or C-terminal LANA's inhibition of p53 activation of the BAX promoter. When N-terminal LANA was wild type, the 1068LKK1070 and 1125SHP1127 substitutions also did not reduce LANA chromosome association or episome persistence. However, when N-terminal LANA binding to chromosomes was modestly diminished, the substitutions in 1068LKK1070 and 1125SHP1127 dramatically reduced both LANA chromosome association and episome persistence. These data suggest a model in which N- and C-terminal LANA cooperatively associates with chromosomes to mediate full-length LANA chromosome binding and viral persistence.

Supramolecular assemblies of two piperazine metal-organic bismuth(III) derivatives: a new precursor for the preparation of bismuth(III) oxide bromide nano-structures

2013 ◽  
Vol 66 (19) ◽  
pp. 3391-3401 ◽  
Author(s):  
Somayeh Khanjani ◽  
Nilofar Soltanzadeh ◽  
Roghayeh Sabahi ◽  
Ali Morsali ◽  
Sang Woo Joo
Keyword(s):  
Supramolecular Assemblies ◽  
Nano Structures ◽  
Metal Organic

scholarly journals Self-assembly of alkyl chains of fatty acids in papermaking systems: A review of related pitch issues, hydrophobic sizing, and pH effects

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 4591-4635
Author(s):  
Martin A. Hubbe ◽  
Douglas S. McLean ◽  
Karen R. Stack ◽  
Xiaomin Lu ◽  
Anders Strand ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Self Assembly ◽  
Review Article ◽  
Ph Effects ◽  
Monolayer Films ◽  
Alkyl Chains ◽  
Ph Values ◽  
Self Association ◽  
Long Chain

This review article considers the role of fatty acids and the mutual association of their long-chain (e.g. C18) alkyl and alkenyl groups in some important aspects of papermaking. In particular, published findings suggest that interactions involving fatty acids present as condensed monolayer films can play a controlling role in pitch deposition problems. Self-association among the tails of fatty acids and their soaps also helps to explain some puzzling aspects of hydrophobic sizing of paper. When fatty acids and their soaps are present as monolayers in papermaking systems, the pH values associated with their dissociation, i.e. their pKa values, tend to be strongly shifted. Mutual association also appears to favor non-equilibrium multilayer structures that are tacky and insoluble, possibly serving as a nucleus for deposition of wood extractives, such, as resins and triglyceride fats, in pulp and paper systems.

scholarly journals Progressive Phosphorylation Modulates the Self-Association of a Variably Modified Histone H3 Peptide

2021 ◽  
Vol 8 ◽  
Author(s):  
George V. Papamokos ◽  
George Tziatzos ◽  
Dimitrios G. Papageorgiou ◽  
Spyros Georgatos ◽  
Efthimios Kaxiras ◽  
...  
Keyword(s):  
Intrinsically Disordered Proteins ◽  
Histone H3 ◽  
Intramolecular Interactions ◽  
Disordered Proteins ◽  
Post Translational Modifications ◽  
Intrinsically Disordered ◽  
Self Association ◽  
Dynamics Simulations ◽  
Peptide Charge

Protein phosphorylation is a key regulatory mechanism in eukaryotic cells. In the intrinsically disordered histone tails, phosphorylation is often a part of combinatorial post-translational modifications and an integral part of the “histone code” that regulates gene expression. Here, we study the association between two histone H3 tail peptides modified to different degrees, using fully atomistic molecular dynamics simulations. Assuming that the initial conformations are either α-helical or fully extended, we compare the propensity of the two peptides to associate with one another when both are unmodified, one modified and the other unmodified, or both modified. The simulations lead to the identification of distinct inter- and intramolecular interactions in the peptide dimer, highlighting a prominent role of a fine-tuned phosphorylation rheostat in peptide association. Progressive phosphorylation appears to modulate peptide charge, inducing strong and specific intermolecular interactions between the monomers, which do not result in the formation of amorphous or ordered aggregates, as documented by experimental evidence derived from Circular Dichroism and NMR spectroscopy. However, upon complete saturation of positive charges by phosphate groups, this effect is reversed: intramolecular interactions prevail and dimerization of zero-charge peptides is markedly reduced. These findings underscore the role of phosphorylation thresholds in the dynamics of intrinsically disordered proteins. Phosphorylation rheostats might account for the divergent effects of histone modifications on the modulation of chromatin structure.

Self-association of insulin and the role of hydrophobic bonding: a thermodynamic model of insulin dimerization

Biochemistry ◽  
1981 ◽  
Vol 20 (15) ◽  
pp. 4354-4361 ◽  
Author(s):  
Y. Pocker ◽  
Subhasis B. Biswas
Keyword(s):  
Thermodynamic Model ◽  
Self Association ◽  
Hydrophobic Bonding

scholarly journals Hemoglobin-spectrin complexes: interference with spectrin tetramer assembly as a mechanism for compartmentalization of band 1 and band 2 complexes

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 366-371 ◽  
Author(s):  
CR Kiefer ◽  
JF Trainor ◽  
JB McKenney ◽  
CR Valeri ◽  
LM Snyder
Keyword(s):  
Blood Cell ◽  
Western Blot ◽  
Red Blood Cell ◽  
Blot Analysis ◽  
Natural Phenomenon ◽  
Cell Aging ◽  
Cell Deformability ◽  
Self Association

The irreducible complexation of hemoglobin with spectrin is a natural phenomenon of red blood cell aging, positively correlating with increasing cell density and decreasing cell deformability. The current study begins to address the role of these complexes in the disruption of membrane skeletal physiology and structure. The effect of bound hemoglobin on spectrin dimer self-association was investigated in vitro. The extent of conversion of isolated spectrin dimers to tetramers was evaluated as a function of peroxide-induced globin complexation before the conversion incubations. The incremental accumulation of tetramer was observed to decrease with increasing peroxide concentration used in the globin complexation step. The role of oxidized heme in this process was made apparent by the inability of carboxyhemoglobin to inhibit tetramer accumulation. A Western blot analysis of naturally formed globin-spectrin conjugates demonstrated irreducible complexes of globin with both bands 1 and 2. The complexes are tentatively designated “h1” and “h2”. This analysis also demonstrated that h1 is completely extractable from cell ghosts, whereas h2 is only 50% extractable. These findings are incorporated into a hypothesis linking globin-spectrin complexation and the consequent inhibition of spectrin dimer self-association to the clustered band 3 senescence antigen (Low et al, Science 227:531, 1985).

Supramolecular Assemblies in Silver Complexes: Phase Transitions and the Role of the Halogen Bond

2020 ◽  
Vol 59 (6) ◽  
pp. 4140-4149
Author(s):  
Giulia Bonfant ◽  
Matteo Melegari ◽  
Davide Balestri ◽  
Francesco Mezzadri ◽  
Vittoria Marzaroli ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Halogen Bond ◽  
Supramolecular Assemblies ◽  
Silver Complexes

scholarly journals DSS1 and ssDNA regulate oligomerization of BRCA2

2020 ◽  
Vol 48 (14) ◽  
pp. 7818-7833 ◽  
Author(s):  
Hang Phuong Le ◽  
Xiaoyan Ma ◽  
Jorge Vaquero ◽  
Megan Brinkmeyer ◽  
Fei Guo ◽  
...  
Keyword(s):  
Replication Fork ◽  
Microscopic Analysis ◽  
Filament Formation ◽  
Electron Microscopic ◽  
Microscopic Imaging ◽  
Cellular Events ◽  
Self Association ◽  
Oligomeric Forms

Abstract The tumor suppressor BRCA2 plays a key role in initiating homologous recombination by facilitating RAD51 filament formation on single-stranded DNA. The small acidic protein DSS1 is a crucial partner to BRCA2 in this process. In vitro and in cells (1,2), BRCA2 associates into oligomeric complexes besides also existing as monomers. A dimeric structure was further characterized by electron microscopic analysis (3), but the functional significance of the different BRCA2 assemblies remains to be determined. Here, we used biochemistry and electron microscopic imaging to demonstrate that the multimerization of BRCA2 is counteracted by DSS1 and ssDNA. When validating the findings, we identified three self-interacting regions and two types of self-association, the N-to-C terminal and the N-to-N terminal interactions. The N-to-C terminal self-interaction of BRCA2 is sensitive to DSS1 and ssDNA. The N-to-N terminal self-interaction is modulated by ssDNA. Our results define a novel role of DSS1 to regulate BRCA2 in an RPA-independent fashion. Since DSS1 is required for BRCA2 function in recombination, we speculate that the monomeric and oligomeric forms of BRCA2 might be active for different cellular events in recombinational DNA repair and replication fork stabilization.

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