G09SecL04Tpc2: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
|||
| Line 13: | Line 13: | ||
Upon infection, OspA is immediately downregulated or can even be turned off. Because of this, vaccinations for OspA are virtually ineffective once spirochetes have entered the host. Downregulation also makes OspA harder to detect; OspA is usually upregulated in the late stages of the disease and leads to more serious inflammatory disorders in the central nervous system. | Upon infection, OspA is immediately downregulated or can even be turned off. Because of this, vaccinations for OspA are virtually ineffective once spirochetes have entered the host. Downregulation also makes OspA harder to detect; OspA is usually upregulated in the late stages of the disease and leads to more serious inflammatory disorders in the central nervous system. | ||
== | == Structural Breakdown == | ||
Outer Surface ProteinA has approximately 270 amino acid residues. In terms of secondary structure, OspA is made up of 21 anti-parallel single layer beta strands and one alpha helix. OspA has three major components to its structure: an n-terminal sandwich, a central sheet, and a c-terminal barrel domains. The n-terminal is often termed as a sandwich due to its jumbled formation of amino acid residues. Most of the beta strands lie on the central sheet. Lastly, the c-terminal is called barrel domains because the three primary loops connect to both sides of the central beta sheet forming a barrel or a hole in the middle. This can be seen by rotating the molecule. | Outer Surface ProteinA has approximately 270 amino acid residues. In terms of secondary structure, OspA is made up of 21 anti-parallel single layer beta strands and one alpha helix. OspA has three major components to its structure: an n-terminal sandwich, a central sheet, and a c-terminal barrel domains. The n-terminal is often termed as a sandwich due to its jumbled formation of amino acid residues. Most of the beta strands lie on the central sheet. Lastly, the c-terminal is called barrel domains because the three primary loops connect to both sides of the central beta sheet forming a barrel or a hole in the middle. This can be seen by rotating the molecule. | ||
The c-terminal is heavily involved in the antigen:antibody complex unlike the n-terminal. The c-terminal houses a protruding ridge of three loops: loop 1 contains residues 203-220; loop 2 contains residues 224-233; loop 3 contains residues 246-257. These loops define the LA-2 (antibody) epitope. More specifically, the loops indicate where the antibody binds to the antigen. | The c-terminal is heavily involved in the antigen:antibody complex unlike the n-terminal. The c-terminal houses a protruding ridge of three loops: loop 1 contains residues 203-220; loop 2 contains residues 224-233; loop 3 contains residues 246-257. These loops define the LA-2 (antibody) epitope. More specifically, the loops indicate where the antibody binds to the antigen. This protruding ridge coupled with OspA’s elongated fold gives the surface protein a high degree of mobility and surface exposure. | ||
== LA-2 Recognition of OspA == | |||
== The Elusiveness of OspA == | == The Elusiveness of OspA == | ||
