scholarly journals Evidence for dimer formation by an amphiphilic heptapeptide that mediates chloride and carboxyfluorescein release from liposomes

2005 ◽  
Vol 3 (4) ◽  
pp. 619 ◽  
Author(s):  
Robert Pajewski ◽  
Riccardo Ferdani ◽  
Jolanta Pajewska ◽  
Natasha Djedovi? ◽  
Paul H. Schlesinger ◽  
...  
Keyword(s):  
Dimer Formation ◽  
Carboxyfluorescein Release

DLTS study of the oxygen dimer formation kinetics in silicon

2009 ◽  
Vol 404 (23-24) ◽  
pp. 4576-4578
Author(s):  
Nikolai Yarykin ◽  
Jörg Weber
Keyword(s):  
Dimer Formation ◽  
Formation Kinetics

scholarly journals Solvent Exposure and Ionic Condensation Drive Fuzzy Dimerization of Disordered Heterochromatin Protein Sequence

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 915
Author(s):  
Jazelli Mueterthies ◽  
Davit A. Potoyan
Keyword(s):  
Phase Separation ◽  
Low Complexity ◽  
Nuclear Bodies ◽  
Disordered Proteins ◽  
Solvent Exposure ◽  
Ion Release ◽  
Dimer Formation ◽  
Eukaryotic Organisms

Proteins with low complexity, disordered sequences are receiving increasing attention due to their central roles in the biogenesis and regulation of membraneless organelles. In eukaryotic organisms, a substantial fraction of disordered proteins reside in the nucleus, thereby facilitating the formation of nuclear bodies, nucleolus, and chromatin compartmentalization. The heterochromatin family of proteins (HP1) is an important player in driving the formation of gene silenced mesoscopic heterochromatin B compartments and pericentric regions. Recent experiments have shown that the HP1a sequence of Drosophila melanogaster can undergo liquid-liquid phase separation under both in vitro and in vivo conditions, induced by changes of the monovalent salt concentration. While the phase separation of HP1a is thought to be the mechanism underlying chromatin compartmentalization, the molecular level mechanistic picture of salt-driven phase separation of HP1a has remained poorly understood. The disordered hinge region of HP1a is seen as the driver of salt-induced condensation because of its charge enriched sequence and post-translational modifications. Here, we set out to decipher the mechanisms of salt-induced condensation of HP1a through a systematic study of salt-dependent conformations of single chains and fuzzy dimers of disordered HP1a hinge sequences. Using multiple independent all-atom simulations with and without enhanced sampling, we carry out detailed characterization of conformational ensembles of disordered HP1a chains under different ionic conditions using various polymeric and structural measures. We show that the mobile ion release, enhancement of local transient secondary structural elements, and side-chain exposure to solvent are robust trends that accompany fuzzy dimer formation. Furthermore, we find that salt-induced changes in the ensemble of conformations of HP1a disordered hinge sequence fine-tune the inter-chain vs. self-chain interactions in ways that favor fuzzy dimer formation under low salt conditions in the agreement with condensation trends seen in experiments.

scholarly journals Interaction of Pestiviral E1 and E2 Sequences in Dimer Formation and Intracellular Retention

2021 ◽  
Vol 22 (14) ◽  
pp. 7285
Author(s):  
Yu Mu ◽  
Birke Andrea Tews ◽  
Christine Luttermann ◽  
Gregor Meyers
Keyword(s):  
Life Cycle ◽  
Cell Surface ◽  
Double Mutant ◽  
Essential Role ◽  
Infectious Clone ◽  
Intracellular Localization ◽  
Dimer Formation ◽  
Covalent Linkage ◽  
Crucial Step ◽  
Retention Signal

Pestiviruses contain three envelope proteins: Erns, E1, and E2. Expression of HA-tagged E1 or mutants thereof showed that E1 forms homodimers and -trimers. C123 and, to a lesser extent, C171, affected the oligomerization of E1 with a double mutant C123S/C171S preventing oligomerization completely. E1 also establishes disulfide linked heterodimers with E2, which are crucial for the recovery of infectious viruses. Co-expression analyses with the HA-tagged E1 wt/E1 mutants and E2 wt/E2 mutants demonstrated that C123 in E1 and C295 in E2 are the critical sites for E1/E2 heterodimer formation. Introduction of mutations preventing E1/E2 heterodimer formation into the full-length infectious clone of BVDV CP7 prevented the recovery of infectious viruses, proving that C123 in E1 and C295 in E2 play an essential role in the BVDV life cycle, and further support the conclusion that heterodimer formation is the crucial step. Interestingly, we found that the retention signal of E1 is mandatory for intracellular localization of the heterodimer, so that absence of the E1 retention signal directs the heterodimer to the cell surface even though the E2 retention signal is still present. The covalent linkage between E1 and E2 plays an essential role for this process.

Dimer formation during the thermo-oxidation of stigmasterol

2010 ◽  
Vol 231 (6) ◽  
pp. 853-863 ◽  
Author(s):  
Karin Struijs ◽  
Anna-Maija Lampi ◽  
Velimatti Ollilainen ◽  
Vieno Piironen
Keyword(s):  
Dimer Formation
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