Efficient conformational space exploration inab initioprotein folding simulation

Abstract

Ab initio protein folding simulation largely depends on knowledge-based energy functions that are derived from known protein structures using statistical methods. These knowledge-based energy functions provide us with a good approximation of real protein energetics. However, these energy functions are not very informative for search algorithms and fail to distinguish the types of amino acid interactions that contribute largely to the energy function from those that do not. As a result, search algorithms frequently get trapped into the local minima. On the other hand, the hydrophobic–polar (HP) model considers hydrophobic interactions only. The simplified nature of HP energy function makes it limited only to a low-resolution model. In this paper, we present a strategy to derive a non-uniform scaled version of the real 20×20 pairwise energy function. The non-uniform scaling helps tackle the difficulty faced by a real energy function, whereas the integration of 20×20 pairwise information overcomes the limitations faced by the HP energy function. Here, we have applied a derived energy function with a genetic algorithm on discrete lattices. On a standard set of benchmark protein sequences, our approach significantly outperforms the state-of-the-art methods for similar models. Our approach has been able to explore regions of the conformational space which all the previous methods have failed to explore. Effectiveness of the derived energy function is presented by showing qualitative differences and similarities of the sampled structures to the native structures. Number of objective function evaluation in a single run of the algorithm is used as a comparison metric to demonstrate efficiency.

Preparation and performance of ceramifiable flame‐retardant silicone sealant

“…The absorption peaks near the wavenumber range of 1257, 1021, 784, and 457 cm À1 correspond to the vibration peaks of Si-CH 3 bonds, Si-O-Si bonds, Si-O bonds, and Al-O bonds, respectively. 19 Furthermore, it can be observed that there are no obvious -OH characteristic absorption peaks in the wavenumber range of 3200 $ 3600 cm À1 . The double bond in the acrylamide functional group can undergo addition reaction with the hydroxyl group in hydroxyl functional groups, thus crosslinking molecular chains in the hydroxy silicone oil into a three-dimensional network structure.…”