Although light chains are found in many multimeric proteins, L chain usually refers to the light chains of immunoglobulins.
These are of 22 kD and of one of two types, kappa or lambda. A single immunoglobulin has identical light chains (2 kappa or 2 lamda). Light chains have one variable and one constant region. There are isotype variants of both kappa and lamda.
(25 Jun 1999)