「Fast and Accurate Comparison of Protein Conformational Ensembles」
Fast and Accurate Comparison of Protein Conformational Ensembles
[IPSJ Transactions on Bioinformatics Vol.18, pp.20-38]
[Abstract]
Molecular dynamics simulations are essential for understanding the properties of protein structures. However, different simulation settings and models can produce different conformational ensembles. Therefore, it is important to compare two protein conformational ensembles. This paper proposes fast heuristic algorithms for comparing such ensembles based on two measures, namely the minimum RMSD and the average minimum RMSD, by utilizing the SMAWK algorithm. The proposed algorithms run in O(n(N+M)) time, where n is the size of the protein, and N and M are the sizes of the two ensembles. The fastest variant of our algorithms is 1,980 times faster than the previous algorithm in our experiments, while maintaining nearly the same level of accuracy.
[Reasons for the award]
The paper “Fast and Accurate Comparison of Protein Conformational Ensembles” proposes a fast and accurate comparison algorithm for an important problem in the computational analysis of protein structural dynamics. For molecular dynamics (MD) simulation data, the authors develop a novel approach that replaces the conventional exhaustive method with O(nNM) time complexity by introducing three heuristic methods—single-direction, dual-direction, and all-direction—achieving a reduced computational complexity of O(n(N+M)). This approach not only significantly reduces computation time compared to existing methods but also demonstrates promising performance in terms of accuracy and error.
The significance of this work can be summarized as follows:
1. Concrete contribution to computational biology and bioinformatics:
Comparing protein conformations is a fundamental task in structural biology, drug discovery, and functional prediction. Conventional algorithms have struggled to scale to large simulation datasets. This study achieves practical acceleration and provides a foundational technology directly applicable to real-world data analysis.
2. Technical originality:
The improvement in computational complexity, based on techniques such as the SMAWK algorithm, goes beyond mere efficiency gains. It represents a sophisticated application of computational geometry and mathematical analysis. The study is also supported by careful experimental evaluation, ensuring high academic reliability.
3. Interdisciplinary impact:
By leveraging information processing techniques to advance computational foundations for problems in the life sciences, this work aligns well with the scope of IPSJ Transactions on Bioinformatics and contributes to research at the interface of information science and life science.
For these reasons, we strongly recommend this paper for the IPSJ Best PaperAward.

Bunsho Koyano
Bunsho Koyano received his Bachelor's and Master's degrees in Engineering, and ph.D degree in Information Science and Technology from the University of Tokyo in 2018, 2020 and 2025, respectively. He joined LY corporation in 2025. He received the SIGBIO Presentation Award from SIGBIO, IPSJ in 2025.

Tetsuo Shibuya
Tetsuo Shibuya, Ph.D. received a Ph.D. of Science from the University of Tokyo, in 1995. His research interests include bioinformatics algorithms and medical data informatics. He was a researcher at IBM Tokyo Research Laboratory from 1997 to 2004. He became an assistant professor in 2004, an associate professor in 2009, and has been a professor since 2020 at the Institute of Medical Science, the University of Tokyo. He was awarded the Funai Science Award, the Microsoft Research New Faculty Award, and the MEXT Science and Technology Award, in 2011, 2011 and 2021 respectively.
