Site-Specific Attachment of Functionalized Poly(ethylene glycol) to the Amino Terminus of Proteins

详细信息    查看全文

• 作者：Hubert F. Gaertner and Robin E. Offord
• 刊名：Bioconjugate Chemistry
• 出版年：1996
• 出版时间：January 1996
• 年：1996
• 卷：7
• 期：1
• 页码：38 - 44
• 全文大小：266K
• 年卷期：v.7,no.1(January 1996)
• ISSN：1520-4812

文摘

A convenient method for the construction of site-specifically modifiedpoly(ethylene glycol)-proteinconjugates is described. This method relies on the ability togenerate a reactive carbonyl group inplace of the terminal amino group. If the protein has N-terminalserine or threonine, this can bedone by very mild periodate oxidation and generates a glyoxylyl group.A method less restricted bythe nature of the N-terminal residue, but which requires somewhatharsher conditions, is metal-catalyzed transamination, which gives a keto group. TheN-terminal-introduced reactive carbonylgroup specifically reacts, under mild acidic conditions, with anaminooxy-functionalized poly(ethyleneglycol) to form a stable oxime bond. Using polymers of differentsize and shape (linear ormultibranched), various conjugates of IL-8, G-CSF, and IL-1ra wereconstructed and furthercharacterized with respect to their biological activity andpharmacokinetic behavior in rats. Unlikemost previous methods, this approach places a single PEG chain at adefined site on the protein. Itshould therefore be more likely to conserve biological activity whenthe latter depends on interactionwith another macromolecule (unlike enzymic activity which oftensurvives multiple PEGylation).