The N-terminal glycine-rich and cysteine-rich regions are essential for antimicrobial activity of crustinPm1 from the black tiger shrimp Penaeus monodon

► The antiproteinase and antibacterial activities of crustinPm1 have been studied. ► Changes of P1 - P1′ amino acids do not make crustinPm1 inhibitory to proteinases. ► Changing the Cys2-Cys3 spacing does not make crustinPm1 inhibitory to proteinases. ► Changes in the WAP domain of crustinPm1 have no effect on antimicrobial activity. ► The Gly-rich and Cys-rich motifs are essential for efficient antimicrobial activity.