The chemical reactions and pathways involving coenzyme gamma-F420-2 (F420-2; coenzyme F420; N-{N-[O-(7,8-didemethyl-8-hydroxy-5-deazariboflavin phospho)-(S)-lactyl]-gamma-L-glutamyl}-L-glutamate), the amide obtained by formal condensation of the carboxylic acid group of F420-0 with the amino group of L-gamma-glutamyl-L-glutamic acid.