The term alpha chain is normally used to indicate one of the subunits of a multi-subunit protein.
[1] The term "chain" is a general term given to any peptide sequence.
[2] It can often refer more specifically to mean: It should be distinguished from the term alpha helix, which refers to one of the common secondary structures found in proteins, along with beta sheet.
This molecular biology article is a stub.
You can help Wikipedia by expanding it.