ABSTRACT
Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 192 countries to mine large data sets. It has now found a 40.8-hertz isolated pulsar in radio survey data from the Arecibo Observatory taken in February 2007. Additional timing observations indicate that this pulsar is likely a disrupted recycled pulsar. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period; the pulsar likely has closely aligned magnetic and spin axes. The massive computing power provided by volunteers should enable many more such discoveries.
ABSTRACT
In the diffusion-collision model, the unfolding rates are given by the likelihood of secondary structural cluster dissociation. In this work, we introduce an unfolding rate calculation for proteins whose secondary structural elements are alpha helices, modeled from thermal escape over a barrier that arises from the free energy in buried hydrophobic residues. Our results are in good agreement with currently accepted values for the attempt rate.
Subject(s)
Models, Molecular , Proteins/chemistry , Biophysical Phenomena , Biophysics , Protein Denaturation , Protein Folding , Protein Structure, Secondary , ThermodynamicsABSTRACT
Proteins with complex folding kinetics will be susceptible to misfolding at some stage in the folding process. We simulate this problem by using the diffusion-collision model to study non-native kinetic intermediate misfolding in a four-helix bundle protein. We find a limit on the size of the pairwise hydrophobic area loss in non-native intermediates, such that burying above this limit creates long-lasting non-native kinetic intermediates that would disrupt folding and prevent formation of the native state. Our study of misfolding suggests a method for limiting the production of misfolded kinetic intermediates for helical proteins and could, perhaps, lead to more efficient production of proteins in bulk.
