Conjugation of carbohydrates to proteins using di(triethylene glycol monomethyl ether) squaric acid ester revisited

• Published in: Carbohydrate research Vol. 456; pp. 24 - 29
• Main Authors: Xu, Peng, Trinh, Michael N., Kováč, Pavol
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.02.2018; Elsevier
• Subjects: Biochemistry & Molecular Biology; Carbohydrates - chemistry; Chemistry; Chemistry, Applied; Chemistry, Organic; Cyclobutanes - chemistry; Esters - chemistry; Glycoconjugates; Glycoconjugates - chemistry; Hydrolysis; Hydrolytic stability; Life Sciences & Biomedicine; Physical Sciences; Proteins - chemistry; Science & Technology; Squarate; Squaric acid chemistry; Glycoconjugates; Squarate; Hydrolytic stability; Squaric acid chemistry; REAGENT; SEROTYPE OGAWA; DIETHYL SQUARATE; ANTIGENS; VIBRIO-CHOLERAE O-1; HEXASACCHARIDE; CARRIER; PROTECTIVE IMMUNITY; TRANSCUTANEOUS IMMUNIZATION; VACCINES
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2017.10.012

Properties of di(triethylene glycol monomethyl ether) squarate relevant to conjugation of carbohydrates to proteins have been reinvestigated and compared with those of dimethyl squarate. It is concluded that the commercially available, crystalline dimethyl squarate remains the most convenient and efficient reagent for conjugation of amine-containing carbohydrates to proteins by a two-step or one-pot conjugation protocol. [Display omitted] •The title squaric acid ester was prepared in the analytically pure state.•Stability of conjugation reagents made from two squarate diesters were compared.•An optimized, one-pot protocol for conjugation of carbohydrates to BSA is proposed.