Introduction

Significance and Background

IgM is one of multiple types of Ig that exist in humans. IgM presents itself on the surface of a B cell as a B Cell Receptor (BCR). Upon binding of an antigen to the BCR, the B cell will activate, proliferate, and produce other Ig compounds. These include IgG, IgD, IgA, and IgE antibodies which all have different roles in the various forms of imune response. This means that the IgM BCR is a critical step in the beggining of an imune response.

The structure of IgM was found using Cryo-EM to visualize each atom in the protein.

History and Discovery

Structure

Transmembrane Region

Constant Region

The constant region of IgM is made up of the 2 . Theese heavy chains form a bridge connecting the FAB fragment or variable region to the transmembrane region. They also act as a wire that the variable region can send a signal through to the intermembrane region as a cellular signal that an antigen has bound.

help hold the heavy chains and Ig Alpha/Beta chains together in the estracellular portion of the intermembrane region.

Variable Region

Relevance