Abstract: An asparagine-linked glycan (N-glycan) detection reagent is provided that utilizes Fbs variants engineered from mouse Fbs proteins, wherein the Fbs variants bind specifically to N-glycosylated peptides and proteins and not to non-glycosylated peptides and proteins, including wherein the Fbs variants bind to N-glycosylated peptides and proteins and not to corresponding non-glycosylated versions of the same peptides and proteins. Compositions and methods for developing and using N-glycosylation-specific analytical, diagnostic, and therapeutic tools are provided.