Mucroporin: cationic host defense peptide that have antibacterial activity by breaking membranes. Is more effective on Gram-positive than on Gram-negative bacteria. Minimum inhibitory concentrations (MIC) are the following: MIC=>100 ug/ml against E.coli AB94012, MIC=>100 ug/ml against P.aeruginosa AB93066, MIC=25 ug/ml against B.thuringiensis AB92037, MIC=50 ug/ml against B.subtilis AB91021, MIC=25 ug/ml against S.aureus AB94004, and MIC=25 ug/ml against the methicillin-resistant coagulase-negative Staphylococcus. Its synthetic analog mucroporin-M1 is more effective. Does not show antiviral activity against any of measles, SARS-CoV, influenza H5N1, hepatitis B and HIV-1 viruses. Mutant mucroporin-M1: can inhibit Gram-positive bacteria at low concentrations and antibiotic-resistant pathogens. Minimum inhibitory concentrations (MIC) are the following: MIC=12.5 ug/ml against E.coli AB94012, MIC=100 ug/ml against P.aeruginosa AB93066, MIC=25 ug/ml against B.thuringiensis AB92037, MIC=25 ug/ml against B.subtilis AB91021, MIC=5 ug/ml against S.aureus AB94004, and MIC=5 ug/ml against the methicillin-resistant coagulase-negative Staphylococcus. Also shows antiviral activities against measles (EC(50) of 7.15 ug/ml), SARS-CoV (EC(50) of 14.46 ug/ml), influenza H5N1 viruses (EC(50) of 2.10 mug/ml), HIV-1, and hepatitis B virus. Forms a helical membrane channel in the prey. Expressed by the venom gland. Belongs to the non-disulfide-bridged peptide (NDBP) superfamily. Short antimicrobial peptide (group 4) family.