7JTI

Interphotoreceptor retinoid-binding protein (IRBP) in complex with a monoclonal antibody (F3F5 mAb5)

Summary for 7JTI

• Entry DOI: 10.2210/pdb7jti/pdb
• EMDB information: 22474
• Descriptor: mAb5 Fab light chain, mAb5 Fab heavy chain, Retinol-binding protein 3, ... (6 entities in total)
• Functional Keywords: irbp, retinoid, interphotoreceptor retinoid-binding protein, antibody, transport protein-immune system complex, transport protein/immune system
• Biological source: Mus musculus (Mouse); More
• Total number of polymer chains: 6
• Total formula weight: 177620.02

Authors

Sears, A.E.,Albiez, S.,Gulati, S.,Wang, B.,Kiser, P.,Kovacik, L.,Engel, A.,Stahlberg, H.,Palczewski, K. (deposition date: 2020-08-17, release date: 2020-10-07, Last modification date: 2024-10-16)

Primary citation

Sears, A.E.,Albiez, S.,Gulati, S.,Wang, B.,Kiser, P.,Kovacik, L.,Engel, A.,Stahlberg, H.,Palczewski, K.
Single particle cryo-EM of the complex between interphotoreceptor retinoid-binding protein and a monoclonal antibody.
Faseb J., 34:13918-13934, 2020

PubMed Abstract: Interphotoreceptor retinoid-binding protein (IRBP) is a highly expressed protein secreted by rod and cone photoreceptors that has major roles in photoreceptor homeostasis as well as retinoid and polyunsaturated fatty acid transport between the neural retina and retinal pigment epithelium. Despite two crystal structures reported on fragments of IRBP and decades of research, the overall structure of IRBP and function within the visual cycle remain unsolved. Here, we studied the structure of native bovine IRBP in complex with a monoclonal antibody (mAb5) by cryo-electron microscopy, revealing the tertiary and quaternary structure at sufficient resolution to clearly identify the complex components. Complementary mass spectrometry experiments revealed the structure and locations of N-linked carbohydrate post-translational modifications. This work provides insight into the structure of IRBP, displaying an elongated, flexible three-dimensional architecture not seen among other retinoid-binding proteins. This work is the first step in elucidation of the function of this enigmatic protein.

PubMed: 32860273
DOI: 10.1096/fj.202000796RR

Experimental method

ELECTRON MICROSCOPY (7.4 Å)