Barley aleurone layers synthesize and secrete several proteases in response to gibberellic acid (GA3). Two major cysteine proteinases designated EP-A (37,000 M(r)) and EP-B (30,000 M(r)) have been described [Koehler and Ho (1988). Plant Physiol. 87, 95-103]. We now report the cDNA cloning of EP-B and describe the post-translational processing and hormonal regulation of both cysteine proteinases...

Activity of the cysteine adducts of the cysteine proteinases papain and thaumatopain can be recovered by treatment with thioredoxin, thioredoxin reductase and NADPH. Recovery of proteinase activity did not occur if any of the components of the thioredoxin system were omitted, or if thioredoxin or thioredoxin reductase were heat-inactivated. Such an enzyme-mediated process may be of significance...

The majority of insects use serine proteinases like trypsin and chymotrypsin as main enzymes to digest their food [1]. These types of peptidases develop their maximum activity under alkaline to neutral pH conditions [2]. In some insect groups the intestinal lumen is acidic and the digestion switched to cysteine-like proteinases such as cathepsin D or L [3,4]. Some Coleoptera groups (e.g. Bruchi...

pistachio green stink bug, acrosternum hegeeri, due to its inflicting damages on crop quantity and quality, is of a great economical importance in pistachio production. on the other hand, a knowledge of digestive enzymes, is quite indispensable in the study and application of new pest management technologies. results of studeies have shown that midgut in this insect is divided into four section...

We have identified and characterized three stage-specific proteinases of Plasmodium falciparum that are active at neutral pH. We analyzed ring-, trophozoite-, schizont-, and merozoite-stage parasites by gelatin substrate PAGE and characterized the identified proteinases with class-specific proteinase inhibitors. No proteinase activity was detected with rings. Trophozoites had a 28 kD proteinase...

In this study we have examined the tissue-destructive proteinases of human pancreatic ductal cancer cell lines derived initially from xenogenic transplants. Cancer cell organelles were isolated following nitrogen cavitation using sucrose density gradient centrifugation. Serine, cysteine, and metalloproteinases were assayed using radiolabeled protein and synthetic substrates. Tumor-induced RBC l...

An ELISA was developed using chicken cystatin as a capture agent for the immunodiagnosis of paragonimiasis and fascioliasis. The assay detected specific antibodies to fluke cysteine proteinases without the need for purified proteinases. An ELISA plate was sensitized with chicken egg white cystatin, incubated with excretory-secretory (ES) products of adult flukes, and standard ELISA procedures w...

Cysteine proteinases and their inhibitors probably play the main role in carcinogenesis and metastasis. The metastasis process need external proteolytic activities that pass several barriers which are membranous structures of the connective tissue which includes, the basement membrane of blood vessels. Activities of the proteinases are regulated by endogenous inhibitors and activators. The imba...