مورد إلكتروني
Molecular assemblies observed by atomic force microscopy
| العنوان: | Molecular assemblies observed by atomic force microscopy |
|---|---|
| بيانات النشر: | Technische Universität Dresden 2007-06-25 2007-03-06 2007-06-25 |
| تفاصيل مُضافة: | Müller, Daniel Hyman, Anthony Lakey, Jeremy Cisneros Armas, David Alejandro |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | We use time-lapse AFM to visualize collagen fibrils self-assembly. A solution of acid-solubilized collagen was injected into the AFM fluid cell and fibril formation was observed in vitro. Single fibrils continuously grew and fused with each other until the supporting surface was completely covered by a nanoscopically well-defined collagen matrix. Laterally, the fibrils grew in steps of ~4 nm suggesting a two-step mechanism. In a first step, collagen molecules associated together. In the second step, these molecules rearranged into a structure called a microfibril. High-resolution AFM topographs revealed substructural details of the D-band architecture. These substructures correlated well with those revealed from positively stained collagen fibers imaged by transmission electron microscopy. Secondly, a covalent assembly approach to prepare membrane protein for AFM imaging that avoids crystallization was proposed. High-resolution AFM topographs can reveal structural details of single membrane proteins but, as a prerequisite, the proteins must be adsorbed to atomically flat mica and densely packed in a membrane to restrict their lateral mobility. Atomically flat gold, engineered proteins, and chemically modified lipids were combined to rapidly assemble immobile and fully oriented samples. The resulting AFM topographs of single membrane proteins were used to create averaged structures with a resolution approaching that of 2D crystals. Finally, the contribution of specific amino acid residues to the stability of membrane proteins was studied. Two structurally similar proteins sharing only 30% sequence identity were compared. Single-molecule atomic force microscopy and spectroscopy was used to detect molecular interactions stabilizing halorhodopsin (HR) and bacteriorhodopsin (BR). Their unfolding pathways and polypeptide regions that established stable segments were compared. Both proteins unfolded exactly via the same intermediates. This 3 Molecular Assemblies observed b |
| مصطلحات الفهرس: | info:eu-repo/classification/ddc/530, ddc:530, Membranprotein, Atomkraftmikroskopie, Einzelmolekül, Kraftspektroskopie, atomic force microscopy, membrane proteins, single molecule force spectroscopy, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| URL: | |
| الإتاحة: | Open access content. Open access content info:eu-repo/semantics/openAccess |
| ملاحظة: | English |
| أرقام أخرى: | SUUSL oai:qucosa:de:qucosa:24925 urn:nbn:de:swb:14-1182777560689-53566 266447899 1091348277 |
| المصدر المساهم: | STAATS U UNIV From OAIster®, provided by the OCLC Cooperative. |
| رقم الأكسشن: | edsoai.on1091348277 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |