Protein-stabilizing and cell-penetrating properties of α-helix domain of 30Kc19 protein

Abstract

The protein-stabilizing and cell-penetrating activities of Bombyx mori 30Kc19 alpha-helix domain (30Kc19 alpha) are investigated. Recently, 30Kc19 protein has been studied extensively as it has both protein-stabilizing and cell-penetrating properties. However, it is unknown which part of 30Kc19 is responsible for those properties. 30Kc19 protein is composed of two distinct domains, an alpha-helix N-terminal domain (30Kc19 alpha) and a beta-trefoil C-terminal domain (30Kc19 beta). The authors construct and produce truncated forms of 30Kc19 to demonstrate their biological functions. Interestingly, 30Kc19 alpha is shown to be responsible for both the protein-stabilizing and cell-penetrating properties of the 30Kc19 protein. 30Kc19 alpha shows even higher protein delivery activity than did whole 30Kc19 protein and has low cytotoxicity when added to cell culture medium. Therefore, based on its multifunctional properties, 30Kc19 alpha can be developed as a novel candidate for a therapeutic protein carrier into various cells and tissues.