Brennan SO, Borg JY, George PM, Soria C, Soria J, Caen J, Carrell RW. New carbohydrate site in mutant antithrombin (7 Ile----Asn) with decreased heparin affinity. FEBS Lett. 1988 Sep 12;237(1-2):118–22. doi: 10.1016/0014-5793(88)80183-2. PMID: 3169232.