The thermophilic actinomycetes are the most common etiological agents causing hypersensitivity pneumonitis. Antigen preparations of these organisms contain proteolytic activity. Further investigation of the proteinases of the thermophilic actinomycetes was undertaken to determine whether this activity may contribute directly to the pathogenesis of hypersensitivity pneumonitis and pulmonary myco...

Porphyromonas gingivalis, and organism implicated in the etiology and pathogenesis of human periodontal diseases, produces a variety of potent proteolytic enzymes, and it has been suggested that these enzymes play a direct role in the destruction of periodontal tissues. We now report that two cell-associated cysteine proteinases of P. gingivalis W12, with molecular masses of approximately 150 k...

Webster, Marion E. (Walter Reed Army Institute of Research, Washington, D. C.), Patricia L. Altieri, David A. Conklin, Sanford Berman, Joseph P. Lowenthal, and Raymond B. Gochenour. Enzymatic debridement of third-degree burns on guinea pigs by Clostridium histolyticum proteinases. J. Bacteriol. 83:602-608. 1962.-An attempt has been made to correlate in vitro activities of Clostridium histolytic...

Two proteinases (proteinases I and II) have been purified from Crotalus adamanteus venom to the stage of electrophoretic homogeneity and proteinase II has been crystallized. The proteinases differ slightly in molecular weight and amino acid composition. Both are metalloenzymes requiring Zn2+ or Ca2+, or both; neither requires thiol compounds for activation. The proteinases are free of esterolyt...

Aspartic proteinases are a well-characterized class of proteinases. In plants, all nascent aspartic proteinases possess a 100-amino-acid, plant-specific sequence (PSS) within their C-terminal lobe, presumed to possess a targeting role in vivo. In this study, the PSS domain from the Arabidopsis thaliana aspartic proteinase was inserted into porcine pepsinogen at the identical location found in n...

The physiology of the gut lumen of the red flour beetle, T. castaneum, was studied to determine the conditions for optimal protein hydrolysis. Although the pH of gut lumen extracts from T. castaneum was 6.5, maximum hydrolysis of casein by gut proteinases occurred at pH 4.2. The synthetic substrate N-alpha-benzoyl-DL-arginine-rho-nitroanilide was hydrolyzed by T. castaneum gut proteinases in bo...

Barley endoproteolytic enzymes are important to germination because they hydrolyze endosperm storage proteins to provide precursors for new protein synthesis. We recently developed an electrophoretic method utilizing gel-incorporated protein substrates to study the endoproteinases of 4-d-germinated barley (Hordeum vulgare L. cv Morex) grain. This work extends those findings to determine the tem...

Fifty-nine mutants with reduced ability to cleave the chymotrypsin substrate N-acetyl-DL-phenylalanine P-naphthyl ester have been isolated in S. cerevisiae. All have reduced levels of one o r more of the three well-characterized proteinases in yeast. All have reduced levels of proteinase C (carboxypeptidase Y). These mutations define 16 complementation groups. HREE proteinases that have been ch...

Members of the Closteroviridae and Potyviridae families of the plant positive-strand RNA viruses encode one or two papain-like leader proteinases. In addition to a C-terminal proteolytic domain, each of these proteinases possesses a nonproteolytic N-terminal domain. We compared functions of the several leader proteinases using a gene swapping approach. The leader proteinase (L-Pro) of Beet yell...

Cross-class inhibition of cysteine proteinases by serpins differs from serpin inhibition of serine proteinases primarily in that no stable serpin-cysteine proteinase complex can be demonstrated. This difference in reaction mechanism was elucidated by studies of the inactivation of the cysteine proteinases, papain and cathepsin L, by the serpin antithrombin. The two proteinases were inactivated ...