Reagents for the Preparation of Chromophorically Labeled Polyethylene Glycol-Protein Conjugates

✍ Scribed by D.L. Ladd; R.A. Snow

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 272 KB
• Volume: 210
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1993.1193

✦ Synopsis

We have developed a new class of reagents (2) for the covalent attachment of polyethylene glycol to proteins. These reagents (2) are the monomethoxypolyethylene glycol esters of 4-fluoro-3-nitrobenzoic acid. The reaction of 2 with lysine (\epsilon)-amino groups produces a chromophore which can be used to quantitate the polyethylene glycol to protein molar ratio. Bovine ((\mathrm{Zn}, \mathrm{Cu})) superoxide dismutase was used as a model protein for conjugation with 2. When monomethoxypolyethylene glycol of average molecular weight 2105 was used, a conjugate was obtained with a polyethylene glycol to protein molar ratio of 8.88 retaining (100 %) of native enzymatic activity; monomethoxypolyethylene glycol of average molecular weight 5210 yielded a conjugate with a polyethylene glycol to protein molar ratio of 9.96 retaining (73 %) of native enzymatic activity. 01993 Academic Press, Inc.