scholarly journals Lateral association and elongation of vimentin intermediate filament proteins: A time-resolved light-scattering study

2016 ◽  
Vol 113 (40) ◽  
pp. 11152-11157 ◽  
Author(s):  
Carlos G. Lopez ◽  
Oliva Saldanha ◽  
Klaus Huber ◽  
Sarah Köster
Keyword(s):  
Light Scattering ◽  
Quantitative Model ◽  
Radius Of Gyration ◽  
Time Resolved ◽  
Intermediate Filament Proteins ◽  
Hierarchical Assembly ◽  
Lateral Association ◽  
Cytoskeletal Filament ◽  
Longitudinal Association ◽  
Scattering Study

Vimentin intermediate filaments (IFs) are part of a family of proteins that constitute one of the three filament systems in the cytoskeleton, a major contributor to cell mechanics. One property that distinguishes IFs from the other cytoskeletal filament types, actin filaments and microtubules, is their highly hierarchical assembly pathway, where a lateral association step is followed by elongation. Here we present an innovative technique to follow the elongation reaction in solution and in situ by time-resolved static and dynamic light scattering, thereby precisely capturing the relevant time and length scales of seconds to minutes and 60–600 nm, respectively. We apply a quantitative model to our data and succeed in consistently describing the entire set of data, including particle mass, radius of gyration, and hydrodynamic radius during longitudinal association.

Time-resolved light scattering study on the gelation process of poly(N-isopropyl acrylamide

Polymer ◽  
1998 ◽  
Vol 39 (13) ◽  
pp. 2769-2775 ◽  
Author(s):  
Tomohisa Norisuye ◽  
Mitsuhiro Shibayama ◽  
Shunji Nomura
Keyword(s):  
Light Scattering ◽  
Time Resolved ◽  
Gelation Process ◽  
Isopropyl Acrylamide ◽  
Scattering Study

Time-Resolved Dynamic Light Scattering Study on the Dynamics of Silica Gels during Gelation Process

2000 ◽  
Vol 33 (3) ◽  
pp. 900-905 ◽  
Author(s):  
Tomohisa Norisuye ◽  
Masao Inoue ◽  
Mitsuhiro Shibayama ◽  
Ryo Tamaki ◽  
Yoshiki Chujo
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Silica Gels ◽  
Time Resolved ◽  
Gelation Process ◽  
Scattering Study

Formation of Branched Calixarene AggregatesA Time-Resolved Static Light Scattering Study

2004 ◽  
Vol 126 (30) ◽  
pp. 9276-9282 ◽  
Author(s):  
Thomas Witte ◽  
Björn Decker ◽  
Jochen Mattay ◽  
Klaus Huber
Keyword(s):  
Light Scattering ◽  
Static Light Scattering ◽  
Time Resolved ◽  
Scattering Study

LIGHT-SCATTERING STUDIES ON ALUMINUM DISTEARATE

1958 ◽  
Vol 36 (11) ◽  
pp. 1584-1595 ◽  
Author(s):  
A. E. Leger ◽  
J. C. Hyde ◽  
H. Sheffer
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Unit Length ◽  
Random Coil ◽  
Linear Molecule ◽  
Radius Of Gyration ◽  
Average Unit ◽  
Scattering Study

A light-scattering study of aluminum distearate in dilute benzene solution suggests that it is a linear molecule of random coil shape. This is further substantiated by intrinsic viscosity – molecular weight data, the constancy of the ratio of the molecular weight to the square of the radius of gyration (Rg), the value of Φ in Flory's intrinsic viscosity – molecular weight relationship, and the close agreement between the theoretical and experimental results found for the unit length of the polymer chain. This average unit length has been calculated to be 4.46 Å.

The Mechanism Of Inhibition Of Fibrin Assembly By Fragment D

1981 ◽  
Author(s):  
J Williams ◽  
R Hantgan ◽  
D Knoll ◽  
J McDonagh ◽  
J Hermans
Keyword(s):  
Light Scattering ◽  
Ionic Strength ◽  
Inhibitory Effect ◽  
Scattering Data ◽  
Radius Of Gyration ◽  
Lateral Association ◽  
Negative Stain ◽  
Fibrin Monomer ◽  
Mechanism Of Inhibition ◽  
Fiber Thickness

Measurements of clot rigidity and fiber thickness indicate that fragment D is a potent inhibitor of fibrin assembly. At physiological ionic strength, D concentrations in excess of 2 moles D/mole fibrinogen lead to a large decrease in clot rigidity and fiber thickness. Above 14 moles D/mole fibrinogen, gelation is inhibited. The molecular weight and radius of gyration of the fibers, determined by light scattering, confirm that short oligomers result, composed of 3 fibrin monomer molecules at 120 moles D/mole fibrinogen and 9 monomers at 14.4 moles D/mole fibrinogen. If D is added to a solution of long protofibrils, no inhibition is observed. Apparently the polymerization of monomers to protofibrils is blocked by D, but not lateral association.Inhibition of protofibril growth was studied in 0.5 M NaCl, pH 7.4, where lateral association is limited by the ionic strength. Stopped-flow light scattering data show a small decrease in the initial rate of polymerization and a slightly prolonged t½ ; the final intensity is less than that for a solution of long protofibrils. This result suggests that fragment D binds to the growing protofibrils with a small effect on the initial polymerization rate, but exerts its inhibitory effect by limiting the later stages of protofibril growth. Measurements of the length of the inhibited protofibrils, calculated from diffusion coefficients obtained by dynamic light scattering, confirm that polymers containing as few as 15 monomers have been obtained. Negative stain electron microscopy also shows a clear limitation of polymer growth under these conditions.Fragment D interferes with fibrin formation by directly blocking the first assembly step: bimolecular polymerization of activated fibrin monomer molecules to form protofibrils. Fragment D apparently occupies a site normally occupied by a fibrin monomer molecule, thus forming a dead-end complex which cannot undergo further assembly.

Sign in / Sign up

Export Citation Format

Share Document