1
|
Geng F, Zhang G, Wang Y, Lü J. Membrane phosphatidylserine allosterically regulates the cytosolic phospholipase A2 activity via an electrostatic-switch mechanism. SOFT MATTER 2022; 18:2203-2210. [PMID: 35226022 DOI: 10.1039/d1sm01791h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Phospholipase A2 (PLA2) is a peripheral membrane protein that plays an essential role in many inflammatory responses. However, the activation mechanisms of PLA2 on the membrane surface have not been fully understood. Herein, we have combined experimental techniques and theoretical approaches to investigate the activation and association of the PLA2 protein on an artificial phospholipid membrane. Using a phosphatidylserine (PS) nanodomain containing membrane to mimic the inflammatory conditions, we found that the activity of cytosolic PLA2s (cPLA2s) increases with higher ratios of PS in the membrane. Molecular dynamics simulations reveal that significant changes in the protein structure are related to negatively charged membranes. In particular, the alteration of negatively charged residues in the C2 domain brings about an opened binding pocket and the catalytic site access to the substrate phospholipid. Meanwhile, the negative residues in the loop 650-665 facilitate the optimal interfacial orientation of the protein with a closed binding pocket on the membrane surface. These results lead us to suggest an electrostatic-switch allosteric mechanism for cPLA2 activation on the cell membrane surface under the inflammatory state.
Collapse
Affiliation(s)
- Feng Geng
- School of Pharmacy, Binzhou Medical University, Yantai 264003, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250000, China
| | - Guangxu Zhang
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250000, China
- CAS key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yadi Wang
- School of Pharmacy, Binzhou Medical University, Yantai 264003, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250000, China
| | - Junhong Lü
- School of Pharmacy, Binzhou Medical University, Yantai 264003, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250000, China
- CAS key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China
| |
Collapse
|
2
|
Tang J, Li Z, Xie M, Zhang Y, Long W, Long S, Wen T, Fang Z, Zhu W, Zheng H, Luo Y, Guan H, Lu H, Zhang J, Yu J, Chen Z. Optical fiber bio-sensor for phospholipase using liquid crystal. Biosens Bioelectron 2020; 170:112547. [PMID: 33010707 DOI: 10.1016/j.bios.2020.112547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/19/2020] [Accepted: 08/22/2020] [Indexed: 10/23/2022]
Abstract
A cost-effective and label-free optical fiber sensor was proposed to detect phospholipase A2 (PLA2) in nM concentration. The sensor is made of an alkoxysilane-modified side-polished fiber (SPF) coated with 4'-pentyl-4-cyanobiphenyl (5CB) and self-assembled phospholipid (L-DLPC). It is found that the relative transmission optical power (RTOP) of the fiber sensor decreases due to the 5CB realignment and redistribution induced by the PLA2 hydrolysis of L-DLPC. The response-time at 5 dB RTOP variation exhibits an exponential dependence on PLA2 concentration, allowing us to detect the PLA2 by the 5 dB-response time. This detection method can reduce the detection time. Compare with the traditional copper-grid sensor, the proposed novel fiber sensor has a lower detection limit (<1 nM). Furthermore, the sensor has good repeat-ability and specificity.The sensor's RTOP variation for PLA2 detection at 1 nM is ~21 times higher than that for five other enzymes (trypsin, amylase, thrombin, glucose oxidase, pepsin) at 1000 nM and lipase at 50 nM. This confirms the sensor's excellent PLA2 specificity. The fiber sensor provides a potential way to be incorporated into micro-flow chips to quantitatively detect biological molecules in a real-time and online manner.
Collapse
Affiliation(s)
- Jieyuan Tang
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Zhibin Li
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Mengyuan Xie
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Yu Zhang
- Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Wenjin Long
- Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Shun Long
- Department of Computer Science, Jinan University, Guangzhou, 510632, China
| | - Tianjin Wen
- Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Zhanxiong Fang
- Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Wenguo Zhu
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Huadan Zheng
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Yunhan Luo
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Heyuan Guan
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Huihui Lu
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Jun Zhang
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China
| | - Jianhui Yu
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China.
| | - Zhe Chen
- Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China; Department of Optoelectronic Engineering, Jinan University, Guangzhou, 510632, China.
| |
Collapse
|