功能和结构分析显示,双域 sialidase 通过补充因子的脱氧化来保护细菌免受补充杀伤
Nicholas D Clark1, Christopher Pham2, Kurni Kurniyati2
1Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, the State University of New York, Buffalo, New York, United States of America.
PLoS pathogens
|September 25, 2023
概括
细菌化酶通过从关键蛋白质中去除酸来解除人体补充系统的武装,使 Porphyromonas gingivalis 等病原体能够逃避免疫防御并引起感染.
科学领域:
- 免疫学 免疫学 免疫学
- 微生物学 微生物学
- 结构生物学 结构生物学
背景情况:
- 补体系统对于对抗细菌感染的天生的免疫力至关重要.
- 细菌病原体使用机制来逃避补充介导的杀死.
- 细菌 sialidases 在补充剂耐药性的作用尚未完全理解.
研究的目的:
- 阐明细菌 sialidases 促进补充耐药性的分子机制.
- 为了研究Porphyromonas gingivalis sialidase (PG0352) 的结构和功能.
主要方法:
- 生物化学测试,以评估在人体补充因子上的利达酶活性.
- 对P. gingivalis sialidase (PG0352) 的结构分析.
- 关于PG0352的活性,基质特异性和结合性质的功能研究.
主要成果:
- 细菌化酶会解析人类补充蛋白和调节剂,从而损害补充功能.
- P. gingivalis PG0352 具有具有 sialidase 和碳水化合物结合模块的双域结构.
- PG0352有效地从人体血清因子中去除酸,保护细菌免受补充介导的杀死.
- PG0352表现出广泛的pH活性和对N-乙神经胺酸 (Neu5Ac) 的偏好.
结论:
- 细菌化酶是关键的毒性因素,可以解除宿主补充系统的作用.
- P. gingivalis PG0352 的结构揭示了向补充的新机制.
- 了解这些相互作用为对抗细菌感染的治疗干预开辟了新的途径.
相关概念视频
Gene Regulation in Microbial Communities: Quorum Sensing
35
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
35
Formation of Lipopolysaccharides
34
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
34
Defense Against Bacterial Pathogens
1.4K
The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
1.4K
Outer Layers of the Cell Envelope
39
The outermost layers of prokaryotic cells play a critical role in their survival, virulence, and interaction with the environment. These layers, often composed of polysaccharides, polypeptides, or proteins, form protective and adhesive structures that vary in organization and function.Capsules and Slime LayersCapsules are highly organized, tightly bound layers of polysaccharides that firmly attach to the bacterial cell wall. These structures serve as formidable protective barriers, preventing...
39
Complement System
2.4K
The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a...
2.4K
Archaeal Cell Wall
37
Archaeal cell walls are structurally and compositionally distinct from their bacterial counterparts, lacking the characteristic peptidoglycan layer found in most bacteria. Instead, archaeal cell walls exhibit remarkable diversity, utilizing materials such as pseudomurein, polysaccharides, and proteins to construct their protective outer layers. This structural flexibility is closely tied to archaea's ecological adaptability.S-Layers: The Common Archaeal Cell WallThe S-layer is the most...
37


