Biomedical subjects

Yinghao Wu

Publications and source records attributed to Yinghao Wu.

3 recordsLinked to original sources

PubMed2003

Conformational flexibility of pyruvate dehydrogenase complexes: a computational analysis by quantized elastic deformational model.

Pyruvate dehydrogenase complex (PDC) is one of the largest multienzyme complexes known and consists of a dodecahedral E2 core to which other components are attached. We report the results of applying a new computational method, quantized elastic deformational model, to simulating the conformational fluctuations of the truncated E2 core, using low-resolution electron cryomicroscopy density maps. The motional features are well reproduced; especially, the symmetric breathing mode revealed in simulation is nearly identical with what was observed experimentally. Structural details of the motions of the trimeric building blocks, which are critical to facilitating the global expansion and contraction of the complex, were revealed. Using the low-resolution maps from electron cryomicroscopy reconstructions, the simulations showed a picture of the motional mechanism of the PDC core, which is an example without precedent of thermally activated global dynamics. Moreover, the current results support an earlier suggestion that, at low resolution and without the use of amino acid sequence and atomic coordinates, it is possible for computer simulations to provide an accurate description of protein dynamics.

Acetyltransferases↗

PubMed2003

Simulation of F-actin filaments of several microns.

Here we report the results of applying substructure synthesis method to the simulation of F-actin filaments of several microns in length. The elastic deformational modes of long F-actin filaments were generated from the vibrational modes of the 13-subunit repeat of F-actin using a hierarchical synthesis scheme. The computationally synthesized deformational modes, in the very low-frequency regime, are in good agreement with theoretical solutions for long homogeneous elastic rods, which confirmed the usefulness of substructure synthesis method. Other low-frequency modes carry rich local deformational features that are unique to F-actins. All these modes thus provide a theoretical basis set for a description of spontaneously occurring thermal deformations, such as undulations, of the filaments. The results demonstrate that substructure synthesis method, as a method for computational modal analysis, is capable of scaling up the microscopic dynamic information, obtained from atomistic simulations, to a wide range of macroscopic length scale. Moreover, the combination of substructure synthesis method and hierarchical synthesis scheme provides an effective way in dealing with complex systems of periodic repeats that are abundant in cells.

Actin Cytoskeleton↗

PubMed2002

Substructure synthesis method for simulating large molecular complexes.

This paper reports a computational method for describing the conformational flexibility of very large biomolecular complexes using a reduced number of degrees of freedom. It is called the substructure synthesis method, and the basic concept is to treat the motions of a given structure as a collection of those of an assemblage of substructures. The choice of substructures is arbitrary and sometimes quite natural, such as domains, subunits, or even large segments of biomolecular complexes. To start, a group of low-frequency substructure modes is determined, for instance by normal mode analysis, to represent the motions of the substructure. Next, a desired number of substructures are joined together by a set of constraints to enforce geometric compatibility at the interface of adjacent substructures, and the modes for the assembled structure can then be synthesized from the substructure modes by applying the Rayleigh-Ritz principle. Such a procedure is computationally much more desirable than solving the full eigenvalue problem for the whole assembled structure. Furthermore, to show the applicability to biomolecular complexes, the method is used to study F-actin, a large filamentous molecular complex involved in many cellular functions. The results demonstrate that the method is capable of studying the motions of very large molecular complexes that are otherwise completely beyond the reach of any conventional methods.

Actins↗