Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. NADPH-cytochrome c reductase was solubilized with bromelain and purified about 400-fold from sucrose/pyrophosphate-washed microsomal fractions from southern armyworm (Spodoptera eridania) larval midguts. 2. The enzyme has a mol.wt. of 70 035 +/- 1300 and contained 2 mol of flavin/mol of enzyme consisting of almost equimolar amounts of FMN and FAD. 3. Aerobic titration of the enzyme with NADPH caused the formation of a stable half-reduced state at 0.5 mol of NADPH/mol of flavin. 4. Kinetic analysis showed that the reduction of cytochrome c proceeded by a Bi Bi Ping Pong mechanism. 5. Apparent Km values for NADPH and cytochrome c and Ki values for NADP+ and 2'-AMP were considerably higher for the insect reductase than for the mammalian liver enzyme. 6. These are discussed in relation to possible differences in the active sites of the enzymes.
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PMID:Purification and characterization of NADPH--cytochrome c reductase from the midgut of the southern armyworm (Spodoptera eridania). 11 98

NADPH-cytochrome c reductase, the flavoprotein component of the liver microsomal mixed-function oxidases, has been compared to the corresponding rat lung microsomal enzyme. Both enzymes were purified by the same methods and have identical ionic strength optima towards the reduction of cytochrome c. Antibody directed against the liver reductase identically inhibited the reduction of cytochrome c and ferricyanide by both enzymes. Double diffusion immunoprecipitation on Ouchterlony plates of deoxycholate-solubilized liver and lung microsomes resulted in converging precipitin lines indicating similar antigenic sites. The apparent molecular weights of the detergent-solubilized and bromelain-solubilized lung enzymes were determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis to be 79 000 and 71 000, respectively. From the above criteria we conclude that the enzymes in these two tissues are very similar or identical proteins.
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PMID:Comparative studies of rat liver and lung NADPH-cytochrome c reductase. 80 27

Development of mitochondrial and microsomal glycerophosphate acyltransferase in the fetal guinea pig lung was investigated. Mitochondrial and microsomal enzyme activity gradually increased from 45 days to 55 days of gestation. The specific activity in the microsomal fraction (8.2 nmol/min per mg protein) then declined until term, but increased again in the 24-h newborn from 2.5 to 6.1 nmol/min per mg protein. Glycerophosphate acyltransferase activity in the mitochondrial fraction declined after 55 days (3.5 nmol/min per mg) to a minimum level at 60 days (1.8 nmol/min per mg), but increased again in the 24-h newborn (4.0 nmol/min per mg). The specific activity of both mitochondrial and microsomal enzyme declined after 24 h after birth until adult levels were attained. Glycerophosphate acyltransferase activity in mitochondria and microsomes from adult lung was 0.8 and 2.0 nmol/min per mg, respectively. Microsomal enzyme activity was consistently inhibited (over 95%) throughout gestation and adulthood by exposure to any one of several proteinases: trypsin, chymotrypsin, papain, bromelain, pronase and nagarse. Although mitochondrial enzyme activity was also inhibited by these proteinases, there was a continuous increase in proteinase-resistant glycerophosphate acyltransferase activity between 45 days of gestation and term. In contrast, adult mitochondrial enzyme activity was stimulated by all the proteinases studied. These results suggest that early in gestation, glycerophosphate acyltransferase lies more exposed on the cytoplasmic side of the mitochondrial outer membrane and as gestation progresses it becomes embedded into the phospholipid bilayer.
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PMID:Development of glycerophosphate acyltransferase in guinea pig lung mitochondria and microsomes. 643 51

Phytocystatins are potent inhibitors of cysteine proteases and have been shown to participate in senescence, seed and organ biogenesis, and plant defense. However, phytocystatins are generally poor inhibitors of the cysteine protease, bromelain, of pineapple (Ananas comosus). Here, we demonstrated that pineapple cystatin, AcCYS1, inhibited (>95%) stem and fruit bromelain. AcCYS1 is a unique cystatin in that it contains an extended N-terminal trunk (NTT) of 63 residues rich in alanine and glutamate. A signal peptide preceding the NTT is processed in vitro by microsomal membranes giving rise to a 27-kD species. AcCYS1 mRNA was present in roots and leaves but was most abundant in fruit. Using immunofluorescence and immunoelectron microscopy with an AcCYS1-specific antiserum, AcCYS1 was found in the apoplasm. Immunoblot analysis identified a 27-kD protein in fruit, roots, and leaves and a 15-kD species in mature ripe fruit. Ripe fruit extracts proteolytically removed the NTT of 27-kD AcCYS1 in vitro to produce the 15-kD species. Mass spectrometry analysis was used to map the primary cleavage site immediately after a conserved critical glycine-94. The AE-rich NTT was required to inhibit fruit and stem bromelain (>95%), whereas its removal decreased inhibition to 20% (fruit) and 80% (stem) and increased the dissociation equilibrium constant by 1.8-fold as determined by surface plasmon resonance assays. We propose that proteolytic removal of the NTT results in the decrease of the inhibitory potency of AcCYS1 against fruit bromelain during fruit ripening to increase tissue proteolysis, softening, and degradation.
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PMID:An extended AE-rich N-terminal trunk in secreted pineapple cystatin enhances inhibition of fruit bromelain and is posttranslationally removed during ripening. 1964 29