Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cathepsin H purified from porcine spleens was studied for its specificity against various peptide and denatured protein substrates. The enzyme degraded all peptide substrates exclusively by an aminopeptidase activity. The enzyme preferentially released NH2-terminal amino acid residues with large hydrophobic (Phe, Trp, Leu, and Tyr) or basic (Arg and Lys) side chains. Amino acids containing small or polar side chains were not released. Peptides with a proline in the NH2-terminal or penultimate positions were not hydrolyzed either. Large polypeptides such as reduced and carboxymethylated soybean trypsin inhibitor and aldolase were not degraded. These results indicate that cathepsin H is an exopeptidase but not an endopeptidase. We propose that the biological role of this enzyme is the degradation of tissue proteins in lysosomes by its aminopeptidase activity.
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PMID:Porcine spleen cathepsin H hydrolyzes oligopeptides solely by aminopeptidase activity. 339 49

Intraperitoneal administration of leupeptin to rats induced a hemoglobin-hydrolyzing protease which was most active at pH 3.5 and was insensitive to pepstatin in various tissues such as the liver, kidney, and muscle, as observed previously in adult rat hepatocytes in primary culture (Tanaka, K., Ikegaki, N., and Ichihara, A. (1979) Biochem. Biophys. Res. Commun. 91, 102-107). The induced acidic protease was purified about 600-fold in 30% yield from rat liver by conventional chromatographic techniques. The purified enzyme appeared homogeneous by polyacrylamide gel electrophoresis in the presence or absence of sodium dodecyl sulfate and was a monomeric protein of Mr = 20,000. The enzyme appeared to be a glycoprotein because its induction was blocked by the addition of tunicamycin to cultures of hepatocytes and because the induced protease was absorbed on concanavalin A-Sepharose and eluted with methylglucoside. It seemed to be present in lysosomes and was fairly stable at various pH values and temperatures. It showed endopeptidase activity on various protein substrates, but scarcely hydrolyzed N-substituted derivatives of arginine. It did not hydrolyze esters, showed no aminopeptidase or carboxypeptidase activity, and did not inactivate glucose-6-phosphate dehydrogenase or aldolase. The enzyme appeared to be a thiol protease, since it was strongly inhibited by sulfhydryl-reactive compounds and N-( [N-(1-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]-agmatine and was not inhibited by reagents specific for carboxyl-, serine-, or metalloproteases. This induced protease could be separated from cathepsins B, D, and H by chromatography. The enzyme was similar to cathepsin L in chromatographic behavior, Mr and pI, but differed from the latter in stability and in its inability to inactivate some enzymes. These results suggest that it differs from any known proteases found previously in rat liver.
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PMID:Purification and characterization of hemoglobin-hydrolyzing acidic thiol protease induced by leupeptin in rat liver. 637 Oct 12

Streptococcus suis is an important swine pathogen responsible for a diverse group of diseases. Studies on vaccines have focused on S. suis serotype 2 strains, which are the most invasive isolates worldwide. However, in China S. suis serotype 9 (SS9) is also a prevalent serotype, which is frequently isolated from diseased pigs. Little is known about immunogenic proteins for SS9. Therefore, an immunoproteomic-based approach was developed to identify immunogenic proteins of SS9. Cell wall proteins extracted from SS9 strain GZ0565 isolated from a diseased pig with meningitis were screened by two-dimensional Western blotting using anti-SS9 sera pooled from specific pathogen-free mice. Protein spots were excised from preparative gels and identified by matrix-assisted laser desorption ionization time-of-flight MS (MALDI-TOF-MS) or MALDI-TOF-TOF-MS, which led to the identification of eight immunogenic proteins (arginine deiminase, extracellular solute-binding protein, translation elongation factor Ts, neprilysin, peptide ATP-binding cassette transporter peptide-binding protein, pyruvate kinase, phosphate acetyltransferase, and fructose-bisphosphate aldolase). These immunogenic proteins, which are encoded by genes that are reasonably conserved among SS9 strains, could be developed as vaccine candidates.
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PMID:Immunoproteomic assay of surface proteins of Streptococcus suis serotype 9. 1837 Oct 70