Related Experiment Video
Updated: Jun 16, 2026

T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Sphericity of a protein via the beta-complex
Deok-Soo Kim1, Jae-Kwan Kim, Chung-In Won
1Department of Industrial Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea. dskim@hanyang.ac.kr
Abstract:
Molecular shape is a fundamental factor in determining the function of a molecule. As proteins tend to fold into globular shapes, the shape descriptor for protein sphericity is important in understanding molecular functions. In this paper, a definition of protein sphericity is introduced based on the recently developed geometric constructs of the beta-complex and beta-shape of a protein. The beta-complex represents the Euclidean proximity among all the atoms in a protein, and the beta-shape is the polyhedron contained within the boundary of the corresponding beta-complex. Hence, the beta-shape determines the proximity among the atoms on the boundary of a protein. Given the volume of a beta-shape, the ratio between the surface area of a sphere with this volume and the surface area of the beta-shape itself is a good measure to classify the sphericity of a protein, especially when the radius of a probe is 3.0 A. The presented measure is invariant to translation and rotation.
Related Concept Videos
Protein Folding
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Globular Proteins
Globular proteins serve many important physiological functions, such as acting as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be soluble in the aqueous...
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...

