Final answer:
There are two types of light chains in antibodies: kappa and lambda. In humans, kappa chains are more prevalent, with a ratio of approximately 2:1 over lambda chains. These light chains, each consisting of variable and constant regions, are fundamental for antibody specificity and immune function.
Step-by-step explanation:
There are two types of light chains in immunoglobulin (antibody) molecules, known as kappa (k) and lambda (λ). The light chain protein of the kappa type consists of 214 amino acids and can be distinguished by the constant and variable sequences, designated as Ck and Vk respectively. Each antibody molecule contains two identical light chains that are either kappa or lambda, but not both, contributing to the antigen-binding sites.
The proportion of kappa and lambda light chains in human immunoglobulins is approximately 2:1, with kappa accounting for about 65%, and lambda for about 35%. The constant region of each light chain consists of one domain, while the variable region (VL) is unique and critical for antigen specificity. These light chains pair with heavy chains, which come in five different types designated by different Greek letters, to form various classes of antibodies.
Understanding light chains and their composition is crucial in studying the function and diversity of antibodies in the immune system. The detailed amino acid sequences and structural domains underline the antigen recognition and binding capabilities of antibodies.