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Preparation and characterization of a soluble dextran α 1 proteinase inhibitor complex
Author(s) -
Mitra G.,
Coan M. H.
Publication year - 1984
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260260508
Subject(s) - dextran , chemistry , protease inhibitor (pharmacology) , hydrogen peroxide , biochemistry , catalase , conjugate , protease , chromatography , proteinase k , enzyme , biology , mathematical analysis , mathematics , human immunodeficiency virus (hiv) , viral load , antiretroviral therapy , immunology
Abstract Purified human α 1 proteinase inhibitor, a plasma glycoprotein with a molecular weight of 5.3 × 10 4 daltons and a major serine protease inhibitor has been covalently coupled to dextrans with molecular weights of 1.77 × 10 4 and 1.03 × 10 4 daltons. The coupled conjugates were soluble in aqueous medium and stable up to 6 months at +5°C. Increased moles of dextran/mole protein ratio during coupling resulted in progressive decreases of inhibitory capacity, immunogenicity, and the association constant ( k assoc ) between the enzyme and the inhibitor. Compared to the native protein, the soluble conjugates showed improved stability at pH 3.0 and heat stability at 60°C. At 60°C, no loss of inhibitory capacity has been seen up to 60 min for the conjugates during which time the native protein lost greater than 90% of its inhibitory capacity. The presence of antioxidant catalase was needed to prevent oxidative degradation by hydrogen peroxide.