Objective: HIV-1 has been a killer disease since two decades ago, while a potential cure has not yet discovered due to the fast mutations of the HIV1 enzymes,i.e reverse transcriptase, integrase, and protease. Apart of HIV-1, malaria has been the biggest cause of death in human and it is mostly found in the East part of Indonesia. There are some enzymes in the food vacuole of Plasmodium falcipa...

Bi-functional inhibitors from the Kunitz-type soybean trypsin inhibitor (STI) family are glycosylated proteins able to inhibit serine and aspartic proteases. Here we report six crystal structures of the wild-type and a non-glycosylated mutant of the bifunctional inhibitor E3Ad obtained at different pH values and space groups. The crystal structures show that E3Ad adopts the typical β-trefoil fo...

A Caenorhabditis elegans gene (asp-1) and cDNA that encode a homologue of cathepsin D aspartic protease were cloned and characterized. The asp-1 mRNA is transcribed from a single exon, and it begins with the SL1 trans-splice leader sequence. The protein (ASP-1) is expressed as a 396-amino acid, 42.7-kDa pre-pro-peptide that is post-translationally processed into a approximately 40-kDa lysosomal...

Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tool...

Proteases have a significant role in the life cycle of parasites and the pathogen-host relationship, being regarded as important virulence factors. In the parasitic nematode Hysterothylacium aduncum proteolytic activity was measured during in vitro development from third larval stage (L3) to mature adult, using DQ red casein as a fluorogenic substrate. Proteolytic activity was detected in all t...

The protease of human immunodeficiency virus has been expressed in Escherichia coli and purified to apparent homogeneity. Immunoreactivity toward anti-protease peptide sera copurified with an activity that cleaved the structural polyprotein gag p55 and the peptide corresponding to the sequence gag 128-135. The enzyme expressed as a nonfusion protein exhibits proteolytic activity with a pH optim...

To invade its definitive host, the mosquito, the malaria parasite must cross the midgut peritrophic matrix that is composed of chitin cross-linked by chitin-binding proteins and then develop into an oocyst on the midgut basal lamina. Previous evidence indicates that Plasmodium ookinete-secreted chitinase is important in midgut invasion. The mechanistic role of other ookinete-secreted enzymes in...

Drought is one of the most severe environmental stresses affecting plant growth and limiting crop production. Although many genes involved in adaptation to drought stress have been disclosed, the relevant molecular mechanisms are far from understood. This study describes an Arabidopsis gene, ASPG1 (ASPARTIC PROTEASE IN GUARD CELL 1), that may function in drought avoidance through abscisic acid ...