The present application relates to a compositions and methods comprising or expressing a MOMO30 protein derived from Momordica balsamina. The MOMO30 protein is about 30 kDa in size, is stable after being autoclaved at 120° C. for 30 min, resists proteolytic cleavage by trypsin, exhibits mannose-sensitive binding HIV gp120, exhibits hemagglutinin and chitinase activity, is capable of activating and stimulating T cell proliferation, is capable of preventing infection by HIV-1 or alleviating symptoms in an HIV-1 infected patients and comprises the amino acid sequence of SEQ ID NO: 1. The MOMO30 protein and/or a nucleic acid encoding the same may be used in methods for preventing or treating viral infections by HIV and other enveloped viruses.
