Fast folders

For these sequences the value of Gj, is less than a certain small value g. For such sequences the folding occurs directly from the ensemble of unfolded states to the NBA. The free energy surface is dominated by the NBA (or a funnel) and the volume associated with NBA is very large. The partition factor <6 is near unify so that these sequences reach the native state by two-state kinetics. The amplitudes in (C2.5.7) are nearly zero. There are no intennediates in the pathways from the denatured state to the native state. Fast folders reach the native state by a nucleation-collapse mechanism which means that once a certain number of contacts (folding nuclei) are fonned then the native state is reached very rapidly [25, 26]. The time scale for reaching the native state for fast folders (which are nonnally associated with those sequences for which topological fmstration is minimal) is found to be... 

It is seen that among different protein-like sequences, we can find significantly larger fractions of the sequences having small characteristic collapse times than for random and random-block sequences with the same 1 1 HP composition. This is true both in the early stages of collapse and in the late stages. Those sequences can be called fast folders . In a sense, dividing the... 

Therefore, we conclude that for the designed copolymers, collapse occurs at a markedly higher kinetic rate, k 1 / ( 1/2) The kinetic properties are clearly related to the sequence distribution. Still it is possible to select champions from the protein-like fast folders. Who are those champions They normally have a larger mean length of hydrophobic and hydrophilic blocks, wider distribution of block length and the average hydrophobicity decreasing towards the chain ends. 

Of course, many random processes generating long sequences might in principle produce fast folders, however, there is a negligible chance that we would be able to find their noticeable fraction. 

This correlation function is shown under different conditions in Fig. 5. In the folded state, the decay of the correlation function is characterized by a relatively narrow dynamical range and short time scales, on the order of 1. The rapid decay of C(t) in this case can be attributed to fluctuations around the native conformation, within the corresponding basin of attraction. The fact that those fluctuations are fast is consistent with the fact that this is a rapid two-state folder. More specifically, the native conformation is expected... 

The tree view serves then as a primary navigation tool for accessing all files stored in the workspace database. It displays a tree of currently opened records in a style just like in conventional explorers, where folders can be collapsed or expanded and files can be moved and copied. In addition, the file tree contains specific popup menus to enable fast access to folder- and file-related operations. 

Sequences for whieh g detectable intermediates and, for all but very small proteins, the rate determining step is the activated transition from one of the CBAs to the native state. The average time scale for transition from these misfolded structures to the native conformation is given by... 

In some high-speed machines, a rotating disc or wheel fed with adhesive by gravity, can apply a line or a zone of adhesive onto fast running sheets. For instance, gluer-folder carton machines use flat discs or discs fitted with pallets to apply water based adhesives on the cardboard sheets at high speed, upto 100 m/min. 

Figure 6. The sketch of the protein folding pathways. The fast (upper) folding pathway includes the formation of native-like collapsed states In, which rapidly convert into the native state N. The fraction of protein molecules, folding along this pathway, is >. For two-state folders, 1. The lower track (followed by 1 - molecules) represents slow pathway(s), which fold by a three-stage kinetic mechanism. At the first stage, nonspecific collapse species Insc form, which later convert into a collection of discrete native-like intermediates . The transition from Ij to the native state is slow and represents the rate-limiting step in the slow pathway. The degree of heterogeneity in the folding pathways depends on the sequence and external conditions.

Sustainable Nuclear Energy Technology Platform (SNETP) Secretariat, October 2010. ESNII The European Sustainable Nuclear Industrial Initiative Demonstration Programme for Fast Neutron Reactors, Concept Paper, http //www.snetp.eu/wp-content/uploads/2014/05/esnii-folder-a4.pdf. 

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