A three-dimensional model of the PsbS protein was built with the help of homology-modeling methods. This protein is also known as CP22 and is associated with the protection of photosystem II of thylakoid from excess quanta of light energy absorbed by the photosynthetic apparatus. PsbS is reported to bind two molecules of zeaxanthin at low pH (<5.0) and is believed to be essential for rapid nonphotochemical quenching (qE) of chlorophyll a fluorescence in photosystem II. An attempt was made to explain the pH modulation of the conformation of protein through salt-bridges Glu(-)(122)-Lys(+)(113) and Glu(-)(226)-Lys(+)(217). Binding of two molecules of zeaxanthin in the three-dimensional model of PsbS is postulated. The molecular mechanism of photoprotection by PsbS is explained through the model.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00894-006-0103-5DOI Listing

Publication Analysis

Top Keywords

three-dimensional model
8
psbs protein
8
excess quanta
8
quanta light
8
light energy
8
energy absorbed
8
absorbed photosynthetic
8
photosynthetic apparatus
8
model zeaxanthin
4
zeaxanthin binding
4

Similar Publications

Periodontitis, a common chronic inflammatory condition caused by bacteria, leads to loss of attachment, resorption of alveolar bone, and ultimately tooth loss. Therefore, reducing bacterial load and fostering alveolar bone regeneration are essential components in the treatment of periodontitis. In this study, we prepared smaller-sized Ag-Metal Organic Frameworks (Ag@MOF) and loaded with sodium alginate (Alg) hydrogel for periodontitis treatment.

View Article and Find Full Text PDF

Hereditary diffuse gastric cancer is characterized by an increased risk of diffuse gastric cancer and lobular breast cancer, and is caused by pathogenic germline variants of E-cadherin and -E-catenin, which are key regulators of cell-cell adhesion. However, how the loss of cell-cell adhesion promotes cell dissemination remains to be fully understood. Therefore, a three-dimensional computer model was developed to describe the initial steps of diffuse gastric cancer development.

View Article and Find Full Text PDF

Ciliary muscle traction during accommodation is able to induce optic nerve head deformation.

Eye (Lond)

January 2025

Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China.

Objectives: To use finite element (FE) modeling and in vivo optical coherence tomography (OCT) imaging to explore the effect of ciliary muscle traction on optic nerve head (ONH) deformation during accommodation.

Methods: We developed a FE model to mimic the ciliary muscle traction during accommodation, and varied the stiffness of the sclera, choroid, Bruch's membrane (BM), prelaminar neural tissue and lamina cribrosa (LC) to assess their effects on accommodation-induced ONH strains. To validate the FE model, OCT images of the right eyes' ONHs from 20 subjects (25 ± 1.

View Article and Find Full Text PDF

Modeling and analysis of explicit dynamics of foot landing.

Med Biol Eng Comput

January 2025

School of Medical Engineering, Department of Cardiology of The First Affiliated Hospital of Xinxiang Medical University, Xinxiang Medical University, Xinxiang, 453003, Henan, China.

The research aims to investigate the mechanical response of footfalls at different velocities to understand the mechanism of heel injury and provide a scientific basis for the prevention and treatment of heel fractures. A three-dimensional solid model of foot drop was constructed using anatomical structures segmented from medical CT scans, including bone, cartilage, ligaments, plantar fascia, and soft tissues, and the impact velocities of the foot were set to be 2 m/s, 4 m/s, 6 m/s, 8 m/s, and 10 m/s. Explicit kinetic analysis methods were used to investigate the mechanical response of the foot landing with different speeds to explore the damage mechanism of heel bone at different impact velocities.

View Article and Find Full Text PDF

Lower limb joint reaction forces during sit-to-stand and stand-to-sit movements in stroke patients with spastic hemiplegia.

J Electromyogr Kinesiol

January 2025

Research Academy of Grand Health, Faculty of Sports Sciences, Ningbo University, Ningbo, China. Electronic address:

Objective: We investigated the characteristics of hip, knee, and ankle joint reaction forces (JRFs) in stroke patients with spastic hemiplegia during sit-to-stand (Si-St) and stand-to-sit (St-Si) movements and explored the relationship between JRFs and joint moments.

Methods: Thirteen stroke patients with spastic hemiplegia and thirteen age-matched healthy subjects were recruited in this study. Three-dimensional motion capture system and force plates were employed to collect kinematic data and ground reaction forces during Si-St and St-Si tasks.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!