The β-subunit of human thyroid stimulating hormone (hTSH) has been synthesized as a single glycoform bearing a chitobiose disaccharide at the native glycosylation site. Key to the successful completion of this synthesis was the introduction of an arginine-tagged acetamidomethyl group, which served to greatly facilitate handling of a glycopeptide fragment with poor aqueous solubility. This general solution to the challenge of working with intractable peptides is expected to find wide use in protein synthesis.