l chain

noun

1. Immunology. either of an identical pair of polypeptides in the antibody molecule that lie parallel to the upper parts of the heavy chain pair and are half the molecular weight.

n.

1. The smaller of the two types of polypeptide chains in immunoglobulins, consisting of an antigen-binding portion with a variable amino acid sequence, and a constant region with an amino acid sequence that is relatively unchanging.

1. The smaller of the two types of polypeptide chains in an antibody molecule. A light chain consists of an antigen-binding portion with a variable amino acid sequence, and a constant region with an amino acid sequence that is relatively unchanging. The light chains are attached to the heavy chains so that the variable regions of both lie alongside each other. Compare heavy chain.