scholarly journals Kinetics of Insulin Aggregation: Disentanglement of Amyloid Fibrillation from Large-Size Cluster Formation

2006 ◽  
Vol 90 (12) ◽  
pp. 4585-4591 ◽  
Author(s):  
Mauro Manno ◽  
Emanuela Fabiola Craparo ◽  
Vincenzo Martorana ◽  
Donatella Bulone ◽  
Pier Luigi San Biagio
2013 ◽  
Vol 91 (2) ◽  
pp. 59-66 ◽  
Author(s):  
Lisa Pokrajac ◽  
J. Robin Harris ◽  
Naghmeh Sarraf ◽  
Michael Palmer

Pyolysin (PLO) belongs to the homologous family of the cholesterol-dependent cytolysins (CDCs), which bind to cell membranes containing cholesterol to form oligomeric pores of large size. The CDC monomer structure consists of 4 domains. Among these, the C-terminal domain 4 has been implicated in membrane binding of the monomer, while the subsequent processes of oligomerization and membrane insertion have primarily been assigned to other domains of the molecule. Recombinantly expressed or proteolytic fragments that span domain 4 of the CDCs streptolysin O and perfringolysin O bind to membranes but fail to oligomerize, and they inhibit the activity of the respective wild-type toxins. We report here that the isolated domain 4 of pyolysin (PLO-D4) not only binds to membranes but also forms oligomers with itself, as well as hybrid oligomers with the full-length toxin. As expected, the pure PLO-D4 oligomers are devoid of pore-forming activity. Surprisingly, however, within hybrid oligomers, PLO-D4 not only fails to inhibit, but even amplifies the hemolytic activity of the full-length toxin, to an extent similar to that of doubling the amount of the full-length toxin alone. We propose that this amplification may be related to the kinetics of the oligomerization reaction. Overall, our findings indicate a greater role of domain 4 in the oligomerization of CDCs than previously demonstrated.


2014 ◽  
Vol 25 (12) ◽  
pp. 1441004 ◽  
Author(s):  
Giuseppe Gonnella ◽  
Antonio Lamura ◽  
Antonio Suma

A systems of self-propelled dumbbells interacting by a Weeks–Chandler–Anderson potential is considered. At sufficiently low temperatures the system phase separates into a dense phase and a gas-like phase. The kinetics of the cluster formation and the growth law for the average cluster size are analyzed.


2016 ◽  
Vol 116 (11) ◽  
Author(s):  
J. Bourgalais ◽  
V. Roussel ◽  
M. Capron ◽  
A. Benidar ◽  
A. W. Jasper ◽  
...  

2002 ◽  
Vol 739 ◽  
Author(s):  
Melissa A. Zubris ◽  
Rina Tannenbaum

ABSTRACTIn this paper we are proposing the synthesis of iron and cobalt nanoalloys via the codecomposition of iron and cobalt carbonyl precursors in the presence of polystyrene as the surface stabilizing agent. In order to form iron-cobalt nanoalloys with no preferential aggregation of metal atoms resulting in phase segregation, the decomposition kinetics of the iron pentacarbonyl and dicobalt octacarbonyl precursors had to be firmly established. The kinetics of cobalt cluster formation has been thoroughly investigated, but data for iron pentacarbonyl decomposition is relatively scarce. To fully understand the formation of the iron nanoclusters, a kinetic study was performed by varying carbonyl concentrations and reaction media in order to establish reaction order and rate constants. Our results suggest this decomposition to be a higher order process (not first order as previously assumed), with a complicated intermediate mechanism, which has been postulated and experimentally verified. By using this kinetic data, we will be able to predict the necessary conditions for the creation of new in-situ iron-cobalt nanoalloys using carbonyl precursors.


Sign in / Sign up

Export Citation Format

Share Document