Food Hydrocolloids for Health (Dec 2023)

Freeze-thaw-induced aggregation of bovine gamma globulin was efficiently inhibited by an intrinsically disordered plant protein dehydrin

  • Honami Osuda,
  • Yuki Kimura,
  • Masakazu Hara

Journal volume & issue
Vol. 3
p. 100108

Abstract

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Immunoglobulin, which is widely used in the formulation of protein drugs, is prone to aggregation due to freezing. The aggregated immunoglobulin exhibits decreased immune-reactivity and increasing immunogenicity. Accordingly, large amounts of excipients are added to immunoglobulin drugs to prevent aggregation. In the present study, we found that an Arabidopsis dehydrin (AtHIRD11), which is a stress-related intrinsically disordered protein, could efficiently inhibit the cryoaggregation of bovine gamma globulin (BGG). AtHIRD11 was 3 to 4 orders of magnitude more efficient than general protectants such as sugars and amino acids at the molar levels. The K-segment, which is a conserved sequence of dehydrin, was one of the protective sites of AtHIRD11. Amino acid substitution analysis indicated that the hydrophobic amino acids contributed to the cryoprotective activity of the K-segment. Moreover, the activity was roughly correlated with the hydropathy scores of hydrophobic amino acids. BGG and the K-segment individually migrated in size exclusion chromatography, showing that the K-segment did not bind to BGG in solution. This suggests that dehydrin may prevent the cryoaggregation of BGG via the K-segment through a transient hydrophobic interaction. Dehydrin may be utilized as an effective stabilizer of immunoglobulin to minimize aggregation under freezing conditions.

Keywords