Bio Reference - Antibodies and CDRs

What are Antibodies?

Antibodies are constructed by pairing heavy and light polypeptide chains. When conducting the antibody search you must be aware of whether your input is classified as a heavy chain or light chain. Within the polypeptide sequences, there are complementarity-determining regions (CDR). To perform an antibody search you must know if your query is a CDR chain on the heavy chain region on the antibody.

What is a CDR?  

CDRs, or Complementarity-Determining Regions, are specific regions of the polypeptide chains within an antibody that determine its specificity for binding to an antigen. These sequences are found within the variable regions of the antibody's heavy and light chains and are crucial for the antigen-binding site. CDRs are highly variable, which allows antibodies to recognize and bind to a diverse array of antigens.

Why use a CDR? 

The variability of CDR's allows the detection of large numbers of antigens. These antigens may be markers for antiviral, antimicrobial, or antitumor activities which if harnessed could lead to a medical and pharmaceutical revolution in drug development. With the emergence of readily available DNA sequencing methods, antibodies can be defined by reference to amino acid/nucleic acid sequences of one or more CDRs. Variants of CDRs can also be claimed to avoid limited patent claims to the precise CDR sequence.  

Light Chain Sequence vs Heavy Chain Sequence  

An antibody binding site is formed by 2 chains of proteins. The outside of the binding edge is formed by a protein with a lighter mass than the inner edge, those composing the heavy chain and light chain of the receptor. Antibodies can also be defined by their heavy and light chain sequences in patents (patent claims based on VH and VL chain sequences are often of a narrow scope).  

Light Chain vs. Heavy Chain CDR 

When doing a CDR search the user must specify if the input is a heavy chain or light chain to specify where on the receptor the protein/nucleotide chain being searched falls.