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24. Top-down proteomics on a microfluidic platform

Author

Zhang, Yuewen, Wright, Maya A., Challa, Pavan K., Saar, Kadi-Liis, Devenish, Sean, Peter, Quentin, and Knowles, Tuomas P. J.

Subjects
Physics - Biological Physics, Quantitative Biology - Biomolecules
Abstract

Protein identification and profiling is critical for the advancement of cell and molecular biology as well as medical diagnostics. Although mass spectrometry and protein microarrays are commonly used for protein identification, both methods require extensive experimental steps and long data analysis times. Here we present a microfluidic top down proteomics platform giving multidimensional read outs of the essential amino acids of proteins. We obtain hydrodynamic radius and fluorescence signals relating to the content of tryptophans, tyrosines and lysines of proteins using a combination of diffusional sizing of proteins, label-free detection and on-chip labelling of proteins with a latent fluorophore in the solution phase. We thereby achieve identification of proteins on a single microfluidic chip by separating and mapping proteins in multidimensional space based on their characteristic physical parameters. Our results have significant implications in the development of easy and rapid platforms to use for native protein identification in clinical and laboratory settings., Comment: 17 pages, 3 figures

Published
2019

35. Investigating protein properties via microfluidic techniques

Author

Zhang, Yuewen and Knowles, Tuomas

Subjects
microfluidics, protein-protein interactions, protein physical properties
Abstract

Proteins are one of the most abundant biomacromolecules and play important roles in bioactivities within organisms, including key functions in DNA replication, immune system response, metabolic reactions and molecular transportation. Proteins fold into their unique compact three-dimensional structures to precisely perform their functions. Knowledge of proteins on their structures and interactions with other molecules or biomacromolecules is fundamental to understand the mechanism of many diseases. Thus, in this thesis, the focus is on studying the physical properties of proteins, and protein interactions using microfluidic techniques. Chapter 1 provides a brief introduction to protein stability and identification as well as their interactions. Then, conventional techniques for studying protein systems are reviewed. Moreover, the principles, designs and applications of microfluidic techniques are introduced. Chapter 2 demonstrates that a microfluidic diffusional sizing device can be employed to study protein interactions with small molecules by measuring the variation of hydrody- namic radius of bovine serum albumin (BSA) in aqueous solution as a function of pH. By simulating the behaviour of folded and unfolded BSA, the relative population of BSA in dif- ferent states can be calculated. In addition, the key residues that regulate the BSA unfolding process are predicted. Furthermore, I utilize a modified microfluidic diffusional sizing device to measure the hydrodynamic radius of Escherichia coli 70S ribosome and study its interactions with antibiotics, such as chloramphenicol. In Chapter 3, a microfluidic device for protein identification is designed to measure the physical parameters of proteins, including the fluorescence intensities of specific amino acids (tryptophan, tyrosine, lysine) and the hydrodynamic radius of proteins. Thus, proteins can be correctly identified in a single microfluidic device. The results have significant implications in development of effective and efficient techniques for precise protein identification in their native state. In Chapter 4, the interactions between a membrane protein (aquaporins) and a small regulator protein (calmodulin) are investigated by detecting the changes of their electrophoretic mobility and diffusivity in microfluidic devices. Then the effective charges of aquaporin0 and its complex with calmodulin are calculated. Finally, the selective binding between calmodulin and different types of aquaporins is investigated based on their relative binding affinities.

Published
2019
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49. Advances in Green Triboelectric Nanogenerators.

Author

Du, Taili, Chen, Zhixiang, Dong, Fangyang, Cai, Hu, Zou, Yongjiu, Zhang, Yuewen, Sun, Peiting, and Xu, Minyi

Subjects
NANOGENERATORS, NATURAL resources, BIODEGRADABLE products, RECYCLABLE material, FOOD waste, ENERGY harvesting, SUSTAINABLE development
Abstract

Triboelectric nanogenerator (TENG), an emerging energy conversion technology, offers innovative pathways for energy harvesting and self‐powered sensing. To achieve superior performance, researchers commonly employ substantial quantities of original or treated polymers, resulting in high energy and precise sensing. Nevertheless, the sustainable development of TENGs faces significant challenges related to environmental compatibility, pollution hazards, and high production and disposal costs. To address this issue, numerous green materials for diverse TENGs are introduced and advanced. These materials may encompass natural resources, household waste, and recyclable materials, among others. Consequently, a review of the progress in TENGs based on green materials, which can be called green TENGs, becomes imperative to advance its sustainable development. To this end, this work comprehensively elucidates the development of green TENGs from the perspective of materials processing and treatment degree for the first time. Various green TENGs, including food waste, discarded daily‐use items, plant organs, biodegradable industrial products, and natural cellulose, are meticulously categorized. This review not only systematically synthesizes the latest research advancements in green TENGs, but also offers insight into their processing methodologies, working characteristics, and potential application scenarios. Finally, it envisions the challenges, proposed solutions, and future research directions for the development of green TENGs. [ABSTRACT FROM AUTHOR]

Published
2024
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50. A Study of Adaptive Threshold Based on the Reconstruction Model for Marine Systems and Their Equipment Failure Warning.

Author

Duan, Xuxu, Gao, Zeyu, Qiao, Zhenxing, Du, Taili, Zou, Yongjiu, Zhang, Peng, Zhang, Yuewen, and Sun, Peiting

Subjects
MARINE equipment, SYSTEM failures, MARINE engines, FAILURE (Psychology), WARNINGS, WASTE gases, NATURAL disaster warning systems, STRUCTURAL health monitoring
Abstract

To achieve the failure warning of marine systems and their equipment (MSAE), the threshold is one of the most prominent issues that should be solved first. In this study, a fusion model based on sparse Bayes and probabilistic statistical methods is applied to determine a new and more accurate adaptive alarm threshold. A multistep relevance vector machine (RVM) model is established to realize the parameter reconstruction in which the internal uncertainties caused by the degradation process and the external uncertainty caused by the loading, environment, and disturbances were considered. Then, a varying moving window (VMW) method is employed to determine the window size and achieve continuous data reconstruction. Further, the model based on Johnson distribution systems is utilized to complete the transformation of the residual parameters and calculate the adaptive threshold. Finally, the proposed adaptive decision threshold is successfully involved in the actual examples of the peak pressure and exhaust temperature of marine diesel engines. The results show that the proposed method can realize the continuous health condition monitoring of MSAE, successfully detect abnormal conditions in advance, achieve an early warning of failure, and reserve sufficient time for decision-making to prevent the occurrence of catastrophic disasters. [ABSTRACT FROM AUTHOR]

Published
2024
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