Proteolytic enzymes are ubiquitous in all organisms and constitute 2–4% of encoded gene products. They are critical for diverse biological processes such as digestion, blood clotting, host defense, pathogenic infection, viral replication, wound healing, and disease progression, to name but a few. Because proteases trigger an irreversible event—the cleavage of a protein—their activity must be ti...

Severa1 storage proteins of potato (Solanum tuberosum L.) tubers have been identified, including severa1 proteinase inhibitors such as proteinase inhibitor I and I1 and the 22-kD protein group (Melville and Ryan, 1972; Bryant et al., 1976; Suh et al., 1990). The 22-kD cathepsin D inhibitor protein of potatoes (PDI) has been purified and characterized (Mares et al., 1989). This glycosylated prot...

Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreo...

Proteolytic activity was detected, using a sensitive radial diffusion plate assay, in the plasma membrane fractions of corn (Zea mays L.) roots and from roots of several other plant species. The proteases could be effectively inhibited in corn with phenylmethane sulfonyl fluoride or chymostatin. Protease activity of oat roots, however, was not significantly reduced by these inhibitors. The resu...

The clearance of cytomegalovirus viraemia in HIV-1-infected patients may partly result from the inhibition of cytomegalovirus protease by HIV-1 protease inhibitors contained in highly active antiretroviral therapy. We used a computational method to calculate the binding affinity of six HIV-1 protease inhibitors to cytomegalovirus protease based on its X-ray crystallography structure. The calcul...

The present study explored the efficacy of Bacillus spp. and protease production for biocontrol of the root-knot nematode Meloidogyne javanica in African violet media. Among 100 bacterial isolates from various soils, the highest nematode mortality was observed for treatments with isolate GM-18, which was identified as Bacillus subtilis based on cultural and morphological characteristics and 16S...

Recently, we cloned a human organic cation transporter, hOCT1, which is expressed primarily in the liver. hOCT1 plays an important role in the cellular uptake and elimination of various xenobiotics including therapeutically important drugs. HIV protease inhibitors are a new class of therapeutic agents. The purpose of this study was to elucidate the interactions of HIV protease inhibitors with h...

Treatment of human immunodeficiency virus type 1 (HIV-1) infection with regimens that include protease inhibitors (PIs) has contributed to marked improvements in HIV-related disease progression and mortality. Five PIs are approved by the US Food and Drug Administration and have potent activity in vitro. PIs with 2 nucleoside analogue reverse transcriptase inhibitors have demonstrated prolonged ...

Adherence to Protease Inhibitors TO THE EDITOR: In an excellent paper, Paterson and colleagues (1) demonstrate that adherence to protease inhibitor therapy of 95% or greater optimizes virologic outcome for patients with HIV infection. In our opinion, however, this conclusion cannot be generalized to all HIV-infected patients, especially those who were previously treated with antiretroviral agen...