Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When leukocyte lysosomal extracts are used as a source of elastase and are combined with a fraction of plasma containing sufficient alpha 1-protease inhibitor (alpha 1-Pi) to inhibit all but 30 to 40% of the elastase amidase activity, elastolysis occurs at 69% of the rate of the uninhibited elastase controls (0.125 M NaCl; pH, 6.5). Proteolysis of elastin requires the presence of NaCl. At pH 8.6, elastolysis is decreased to 30 to 40% of free elastase controls by 1.0 M NaCl. At pH 6.5, on the other hand, elastolysis is increased to 83% of the control values by these higher NaCl concentrations. The activity of human leukocyte myeloperoxidase is optimal at pH 6 to 6.5 and at NaCl concentrations between 0.25 and 1.0 M. Purified myeloperoxidase, alpha 1-Pi, and elastase, in the presence of NaCl and hydrogen peroxide, can reproduce this phenomenon at pH 6.5, suggesting that the occurrence of elastolysis in lysosomal extract-plasma mixtures may in part be a result of the oxidative inactivation of alpha 1-Pi by myeloperoxidase present in the lysosomal extract. Human ceruloplasmin, the major antioxidant of plasma, inhibits this myeloperoxidase-dependent reaction, without interfering either with free elastase activity or with the appearance of activity in plasma-lysosomal extract mixtures at pH 8.6. The "antioxidant" activity of ceruloplasmin is inhibited by azide. These results suggest that antioxidants such as ceruloplasmin may be an important determinant of lung defense in persons chronically exposed to oxidants.
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PMID:Ceruloplasmin: plasma inhibitor of the oxidative inactivation of alpha 1-protease inhibitor. 628 6

Elastases are unique among the proteases in that they are capable of hydrolyzing the scleroprotein elastin. The enzymes include pancreatic elastases 1 (Protease E) and 2, and neutrophil elastase. These three elastases also have esterase and amidase activity toward synthetic substrates such as succinyl-trialanine-p-nitroanilide. Although the three enzymes are similar to each other in enzyme activity, they are quite different in immunoactivity. Therefore, each elastase has its own specific immunoassay either by RIA or EIA. Serum immunoreactive pancreatic elastases reflect disease conditions of pancreatic diseases, especially acute pancreatitis and pancreatic cancer. On the other hand, serum neutrophil elastase increases in various inflammatory diseases or conditions.
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PMID:[Elastase]. 760 77

Micrococcus luteus isolated from human skin secretes an alkaline protease which degrades elastin. M. luteus protease (MLP) was produced in the late logarithmic and stationary phases of growth. MLP, purified to homogeneity by a three-step process, had a molecular mass of 32,812 Da and an isoelectric point of 9.3. MLP was active and highly stable in solution for 24 h from pH 6.0 to 10.5; it had maximal activity at temperatures between 57 and 59 degrees C. The presence of calcium in the solution was essential for enzyme activity and to prevent autolysis. Optimal activity occurred between pH 9.0 and 9.5, with 60% maximal activity from pH 6.5 to 11.0. The enzyme was inhibited by the serine enzyme inhibitors phenylmethylsulfonyl fluoride and chymostatin but not by the metalloenzyme inhibitor 1,10-phenanthroline or sulfhydryl enzyme inhibitors. Casein, bovine serum albumin, ovalbumin, beta-lactoglobulin, and elastin were digested by the protease while collagen and keratin were resistant to digestion. MLP demonstrated both esterase and amidase activity on synthetic peptide substrates. MLP preferentially cleaved the Leu(15)-Tyr(16) and Phe(24)-Phe(25) bonds of the oxidized beta-chain of insulin. Longer digests of insulin and the pattern of activity against synthetic substrates suggest that MLP has a cleavage specificity for bulky, hydrophobic, or aromatic amino acids in the P(1) or P(1)' positions. Amino acid sequences from the N-terminus and internal peptides of MLP were unique.
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PMID:Purification and characterization of a unique alkaline elastase from Micrococcus luteus. 1064 68