Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Specific trypsin substrates (esters, anilides, amides, peptides) were shown to accelerate deacetylation of monoacetylated trypsin. The amidase activity of monoacetyl-, monopropyonyl-, and tetraformyl-trypsin was not manifested if the amidase activity of native enzyme was suppressed in these preparations by the ester substrates (benzoylarginine ethyl ester or p-nitrophenyl acetate). Therefore the differences in the residual amidase and esterase activities of these acylated trypsin preparations found earlier did not contradict the universality of the acylenzyme mechanism. These differences are due to the strong deacylating effect of specific substrate in its complex with the enzyme modified with nonspecific acyl residue. The latter fact is suggested to be an experimental confirmation of the "induced fit" hypothesis.
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PMID:[The nature of differences in amidase and esterase activities of some acyltrypsins]. 120 61

The structures of the choline-dependent pneumococcal murein hydrolases, LYTA amidase and CPL1 lysozyme, and the choline-independent CPL7 lysozyme were analysed by controlled proteolytic digestions. The trypsin cleavage of the CPL1 and CPL7 lysozymes produced two resistant polypeptides, F1 and F7 respectively, corresponding to the N-terminal domain of the enzymes, whereas the amidase LYTA was completely hydrolysed by the protease. Interestingly, the F1 and F7 fragments showed a low, but significant, choline-independent lysozyme activity. Choline reduced the rate of proteolytic hydrolysis of choline-dependent enzymes, suggesting that the C-terminal choline-binding domain adopts a more resistant conformation in the presence of the ligand. On the other hand, the regions encoding the N-terminal domains of the three enzymes have been cloned and expressed in Escherichia coli, showing that these domains adopt an active conformation even in the absence of their C-terminal domains. The lower activity shown by the catalytic domains when compared with that of the complete enzymes suggests that the acquisition of a substrate-binding domain represents a noticeable evolutionary advantage for enzymes that interact with polymeric substrates, allowing them to achieve a higher catalytic efficiency. These results strongly reinforce the hypothesis that the pneumococcal murein hydrolases have been originated by fusion of two structural and functional independent domains, and provide new experimental support to the theory of modular evolution of proteins.
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PMID:Studies on the structure and function of the N-terminal domain of the pneumococcal murein hydrolases. 135 Dec 40

Intraduodenal instillation of raw soybeans stimulated pancreatic proteinase secretion in humans. Raw soybeans almost abolished the activity of chymotrypsin and severely reduced (50%) the tryptic activity. Immunoreactive tryptic and chymotryptic material simultaneously appeared in amounts 2 to 4 times basal concentrations. This increase, demonstrated with rocket immunoelectrophoresis, was begun within the first 10 min of soybean instillation. The enhanced secretion also persisted throughout the succeeding saline instillation, and it is suggested that the presence of Kunitz trypsin inhibitor contributed to this postprandial stimulation. An amidase that hydrolyzes low-molecular-weight substrates (i.e., benzoyl-arginine p-nitroanilide) was found in raw soybeans. Its low activity was not assumed to substantially bias standard trypsin assays. The increased proteinase secretion was, as previously published, not preceded by an elevated plasma cholecystokinin concentration. The raw soybeans also caused a nonparallel secretion of amylase and proteinases. Nervous, perhaps cholinergic, regulation mediates the inhibitor-stimulated proteinase secretion in humans. This stimulation yields both a general increase of proteinases and also a specific inhibitor-resistant trypsin. This is consistent with the physiologic need for proenzyme-activation in the presence of inhibitors and for restoration of the proteolytic capacity of the duodenal juice.
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PMID:Raw soybeans stimulate human pancreatic proteinase secretion. 137 45

An enzyme preparation with affinity to a lysine column was detected from a DEAE-cellulose-adsorbed preparation of human seminal plasma containing plasminogen and plasmin. Two kinds of trypsin-like acidic arginine amidase activity with different affinity to lima bean trypsin inhibitor (LBTI) and aprotinin affinity column were detected from the DEAE-cellulose-adsorbed preparation after treatment of the lysine column. Two kinds of trypsin-like basic arginine amidase activity were also separated by the above-mentioned affinity adsorptions from a CM-cellulose-adsorbed preparation of human seminal plasma. The effect of calcium chloride on these two enzymes was different from human acrosin.
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PMID:Trypsin-like arginine amidases including plasminogen and plasmin in human seminal plasma by affinity adsorption and elution. 153 Mar 64

A full-length cDNA encoding human salivary-gland preprokallikrein was inserted into the baculovirus Autographa californica nuclear polyhedrosis virus downstream of the polyhedrin promoter. The gene was expressed in transfected Spodoptera frugiperda cells and the recombinant product secreted into the culture medium. By alternating anion-exchange chromatography and gel-filtration steps, twice repeated, prokallikrein was purified to homogeneity, which was confirmed by amino acid analysis and N-terminal sequence determination. The prepropeptide was processed correctly, including the removal of the signal peptide. The resulting proenzyme was found to be glycosylated, had a molecular mass of 35 kDa and an isoelectric point of 4.6. The yield of purified recombinant protein reached a level of 5 mg/l insect cell culture. After trypsin digestion of prokallikrein, the biological activity of the released kallikrein was demonstrated by its specific amidase, esterase and kininogenase activity. The expression and purification of prokallikrein, as described here, offers the opportunity to study the proenzyme activation through protein engineering techniques in detail.
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PMID:Purification and characterization of human salivary-gland prokallikrein from recombinant baculovirus-infected insect cells. 158 72

1. PSTI, two chymotrypsinogens and two trypsins were purified to homogeneity by acid extraction, salt fractionation, SP-Sephadex C-50 chromatography and RP-HPLC. 2. A third chymotrypsinogen, a trypsinogen and another trypsin were purified using an alkaline extraction procedure, followed by Trasylol- and Benzamidine-Sepharose affinity chromatography and hydroxylapatite chromatography. 3. The enzymes differed in amino acid composition as well as in specific activities towards synthetic amidase and esterase substrates. 4. N-terminal amino acid sequences were determined for one chymotrypsinogen and one trypsin.
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PMID:The isolation and partial characterization of trypsinogen, pancreatic secretory trypsin inhibitor and multiple forms of chymotrypsinogen and trypsin from the pancreas of the ostrich (Struthio camelus). 161 78

The peritoneal exudate formed during experimental pancreatitis is toxic when administered intraperitoneally or intravenously to other animals. Overwhelming of the peritoneal antiprotease defences by proteolytic enzymes released from the pancreas may be a key factor responsible for this toxicity and is examined in the current study. Human pancreatitis exudates possessed tryptic amidase activity indicating trypsinogen activation. The trypsin inhibitory capacities of exudates were reduced indicating a degree of consumption of the peritoneal antiproteases. Of 21 exudates examined, three showed marked reduction of their trypsin inhibitory capacity indicating almost complete consumption of their antiproteases. All three patients were shocked at the time of sampling, two dying of fulminant pancreatitis within 24 h. Overwhelming of the peritoneal antiproteases was not confirmed, but may occur in a few instances where proteolytic enzyme release or zymogen activation continues. Intraperitoneal administration of exogenous antiproteases prolongs survival in rats with pancreatitis and has been suggested as a therapy in man. The current data suggests that few patients are likely to benefit from such an approach.
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PMID:Role of the protease-antiprotease balance in peritoneal exudate during acute pancreatitis. 170 61

Activity of tissue and blood plasma kallikreins as well as total content of their inactive precursors were studied in rabbit eye structures and media: iris, ciliary body, cornea, vascular striatum, retina, aqueous humor, tear liquid, lacrimal gland by means of fluorimetric procedure using Z-Phe-Arg-MCA as a substrate. Dissimilar capacity of the trypsin soya bean inhibitor and of aprotinin (basic inhibitor of Kunitz type) to inhibit tissue and blood plasma kallikreins enabled to differentiate the enzymatic activity. Lacrimal gland contained the highest activity of tissue kallikrein which amounted to 70% of total Z-Phe-Arg-MCA-hydrolyzing activity of the homogenate. Total Z-Phe-Arg-MCA-amidase activity and activity of individual kallikreins was distinctly lower in all the eye structures and media studied as compared with that of lacrimal gland. Activity of tissue kallikrein was higher than blood serum kallikrein activity in iris, ciliary body, vascular striatum, retina and conjunctiva. The highest content of prekallikreins was found in conjunctiva, aqueous humor, iris and ciliary body. Tissue and blood plasma kallikrein-kinin systems appear to carry out dissimilar functions in eye tissue structures; they are apparently involved in pathogenesis of some eye diseases.
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PMID:[Activity of tissue and plasma kallikrein and level of their precursors in eye tissue structures and media of healthy rabbits]. 172 76

Human pancreatic elastase 1 (E1) is a glycoprotein containing two potential N-glycosylation sites, one of which carries a carbohydrate moiety [Wendorf, Geyer, Sziegoleit & Linder (1989) FEBS Lett. 249, 275-278]. In order to study its glycosylation, glycoprotein isolated from post-mortem pancreas tissue of 75 donors was digested with trypsin. Oligosaccharides were liberated from resulting glycopeptides by treatment with peptide-N4-(N-acetyl-beta-glycosaminyl)-asparagine amidase F, radiolabelled by reduction with KB3H4 and separated by h.p.l.c. and gel filtration. Major oligosaccharide alditol fractions, representing 67.8 mol% of total glycans, were characterized by methylation analysis and sequential degradation with exoglycosidases. The results revealed that about two-fifths of the partially truncated, mainly biantennary, complex-type glycans found comprised blood group A, B, Lea (or X), difucosyl A or difucosyl B determinants, which could be assigned to lactosamine antennae linked to Man(alpha 1-3)- residues of the sugar chains.
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PMID:Carbohydrate structure of human pancreatic elastase 1. 189 43

Mammalian DHOase (S-dihydroorotate amidohydrolase, EC 3.5.2.3) is part of a large multifunctional protein called CAD, which also has a carbamoyl-phosphate synthetase [carbon-dioxide: L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating), EC 6.3.5.5] and aspartate transcarbamoylase (carbamoyl-phosphate: L-aspartate carbamoyltransferase, EC 2.1.3.2) activities. We sequenced selected restriction fragments of a Syrian hamster CAD cDNA. The deduced amino acid sequence agreed with the sequence of tryptic peptides and the amino acid composition of the DHOase domain isolated by controlled proteolysis of CAD. Escherichia coli transformed with a recombinant plasmid containing the cDNA segment 5' to the aspartate transcarbamoylase coding region expressed a polypeptide recognized by DHOase domain-specific antibodies. Thus, the order of domains within the polypeptide is NH2-carbamoyl-phosphate synthetase-DHO-aspartate transcarbamoylase-COOH. The 334-residue DHOase domain has a molecular weight of 36,733 and a pI of 6.1. A fragment of CAD having DHOase activity that was isolated after trypsin digestion has extensions on both the NH2 (18 residues) and COOH (47-65 residues) termini of this core domain. Three of five conserved histidines are within short, highly conserved regions that may participate in zinc binding. Phylogenetic analysis clustered the monofunctional and fused DHOases separately. Although these families may have arisen by convergent evolution, we favor a model involving DHOase gene duplication and insertion into an ancestral bifunctional locus.
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PMID:Mammalian dihydroorotase: nucleotide sequence, peptide sequences, and evolution of the dihydroorotase domain of the multifunctional protein CAD. 196 94


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