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

Hamsters were exposed to 30 ppm nitrogen dioxide (NO2) for 2 and 50 days and sacrificed. Pulmonary lavage was carried out on a portion of each group to obtain an alveolar macrophage fraction. Proteolytic activity (P.A.), as measured by caseinolysis at pH 3.0 and pH 5.0, increased nearly twofold in the 2-day NO2 lung extracts and fourfold in the 50-day NO2 samples. P.A. in macrophage extract at pH 3.0 increased tenfold with both 2- and 50-day NO2 exposure. Lung extract hydrolysis of specific esterase and amidase substrates and susceptibility to activators and inhibitors of proteolytic enzymes are consistent with the presence of lysosomal cathepsin A, B1, B2, C, D, and E. The lack of NO2-induced increases in P.A. at physiologic values of pH may be the basis of the lack of significant pulmonary tissue destruction observed in rodents exposed to NO2 for 2 and 50 days.
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PMID:Nitrogen dioxide and pulmonary proteolytic enzymes. Effect on lung tissue and macrophages. 1 98

A mutant of yeast lacking proteinase C (carboxypeptidase Y) activity has been found by using a histochemical stain to screen mutagenized colonies. This defect segregates 2:2 in meiotic tetrads. Cell extracts lacked the esterolytic, amidase, and proteolytic activities associated with proteinase C. The absence of proteinase C does not affect mitotic growth and has no obvious effect on the formation of viable ascospores or meiotic segregation. The mutant grows on peptides known to be cleaved by proteinase C in vitro. This finding is consistent with the idea that other enzymes exist in vivo with overlapping substrate specificities.
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PMID:Proteinase C (carboxypeptidase Y) mutant of yeast. 5 Oct 20

Cathepsin A [EC 3.4.2.-] of small molecular size (cathepsin A, S) has been purified about 800-fold from pig kidney by procedures including chromatographies on DEAE-Sephadex, SP-Sephadex, and Sephadex G-150. 1. The homogeneity of the purified enzyme was proved by ultracentrifugation and polyacrylamide gel electrophoresis. The molecular weight (100,000) and isoelectric point (pI=5.0) were estimated. 2. The enzyme was remarkably stabilized by sucrose and KCl, and was most stable at pH 5-5.5 in the presence of both stabilizers. The enzyme had not only peptidase activity but also esterase and amidase activity; it was optimally active at pH 5.2 for peptide hydrolysis and at pH 8 for the hydrolysis of esters and amides. 3. Diisopropyl fluorophosphate and iodoacetamide completely inhibited these three activities. 4. The enzyme hydrolyzed various benzoyl- and benzyloxycarbonyl-dipeptides with neutral, acidic, and basic amino acids, and proline in the C-terminal position. The carboxypeptidase nature of the enzyme was proved by its action on an oligopeptide. 5. Several enzymatic properties of cathepsin A, S were almost the same as thoas of cathepsin A of large molecular size (cathepsin A, L) and the crude homogenate.
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PMID:Purification and some properties of cathepsin A of small molecular size from pig kidney. 23 65

The combination method of carboxypeptidase Y digestion and fast atom bombardment (FAB) mass spectrometry is described for the identification of C-terminal amino acid amides in peptides. Carboxypeptidase Y has amidase activity as well as exopeptidase activity in the same digestion buffer condition. Based on this concept, we develop a new technique which can definitively and easily identify the C-terminal amino acid amides. This method obviates the need for several complicated steps occurring in previous methods, but improves sensitivity, and enables exact identification of the amino acid amide by the difference of molecular mass. Analyses of carboxypeptidase Y digested peptides, not liberated free amino acid amides, were carried out by fast atom bombardment mass spectrometry. The use of truncated peptides by fast atom bombardment mass spectrometry in C-terminal amino acid amide determination gives several advantages over analyses of the liberated amino acid amides. The C-terminal amino acid amides of Allantostatin I (Leu-NH2), alpha-Melanocyte Stimulating Hormone (Val-NH2), and Ranatensin (Met-NH2) are unequivocally determined at a level of 0.90-2.3 nmol per peptide. This approach is based on entirely different principles than the previous approaches.
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PMID:Identification of the C-terminal amino acid amides by carboxypeptidase Y digestion and fast atom bombardment mass spectrometry. 770 6

To clarify the substrate-recognition mechanism of carboxypeptidase Y, Fmoc-(Glu)n Ala-OH (n = 1 to 6), Fmoc-(Glu)n Ala-NH2 (1 to 5), and Fmoc-Lys(Glu)3Ala-NH2 were synthesized, and kinetic parameters for these substrates were measured. Km for Fmoc-peptides significantly decreased as peptide length increased from n = 1 to n = 5 with only slight changes in kcat. Km for Fmoc-(Glu)(5,6)Ala-OH were almost the same as one for protein substrates described previously (Nakase et al., Bull. Chem. Soc. Jpn., 73, 2587-2590). These results show that the enzyme has six subsites (S1' and S1-S5). Each subsite affinity calculated from the Km revealed subsite properties, and from the differences of subsite affinity between pH 6.5 and 5.0, the residues in each subsite were predicted. For Fmoc-peptide amide substrates, the priorities of amidase and carboxamide peptidase activities were dependent on the substrate. It is likely that the interactions between side chains of peptide and subsites compensate for the lack of P1'-S1' interaction, so the amidase activity prevailed for Fmoc-(Glu)(3,5)Ala-NH2. These results suggest that these subsites contribute extensively to substrate recognition rather than a hydrogen bond network.
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PMID:Substrate recognition mechanism of carboxypeptidase Y. 1179 20

A simple system is introduced to produce dipeptides continuously by enzyme catalyzed condensation of amino acid esters and amino acid amides. Synthesis of N-terminal free dipeptide-amides is achieved by means of carboxypeptidase Y. The peptide-amide is deamidated utilizing a newly isolated peptide-amide is deamidated utilizing a newly isolated peptide-amidase. Separation of substrates and products is accomplished by anion-exchange chromatography. Modeling of the reactions shows that the two reactions have to be carried out in a cascade of two reactors in order to prevent hydrolysis of the peptide by the carboxypeptidase. Continuous production of Kyotorphin (H-TyrArg-OH) with a space-time yield of 257 g/L.d shows the feasibility of this concept.
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PMID:A two-step enzymatic synthesis of dipeptides. 1860 Sep 23