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

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Amphipathic enzymes, invertase (EC 3.2.1.26), 8-amylase (EC 3.2.1.3), and alkaline phosphatase (EC 3.1.3.1), were purified from the rat small intestinal mucosa as trypsin and Triton forms, the catalytic and regulatory characteristics of which were compared in rats and in drosophila. Differences in the catalytic propertiis of the two enzyme forms were demonstrated, which suggested that the hydrophobic part of the enzyme was involved in maintaining optimal conformation of the catalytic part. Many modifiers have beenfound to influence the Triton rather than the trypsin form of the enzyme. It is therefore suggested that the hydrophobic sub-units of the enzymes might be involved in transmitting information from the cytoplasm into the external surface of the membrane, the cell in this way regulating the activity of surface enzymes. If this is indeed the case, it is suggested that the hydrophobic part performs functions not only of external but also of internal regulation.
...
PMID:Catalytic and regulatory properties of the Triton and trypsin forms of the brush border hydrolases. 4 Aug 47

Macroporous glasses with pore sizes from 400-1000 A appropriate for protein binding were produced and characterized by a thermal demixing procedure and alkaline after treatment. To achieve a covalent binding capacity relative to proteins, the gamma-aminopropyl derivative was allowed to react with 4-maleinimido benzoylic chloride to give preparations containing, in addition to maleinimide residues, acid chloride structures for the protein binding. A preparation of 400 A pore size was tested for its protein binding capacity relative to bovine serum albumin and trypsin. Furthermore, the capacity of binding glucoamylase from Endomycopsis bispora in active form was studied.
...
PMID:[Immobilization of proteins on macroporous glasses involving maleinimide as the anchoring group]. 34 50

It is shown that certain key enzymes in membranous digestion (alkaline phosphatase, peptidase, gamma-amylase) are allosteric and ensure the autoregulation and the homoeostasis of the final stages of hydrolysis and of the initial stages of nutrient transport. This mechanism was evidenced not only in vertebrates (mammals, birds, fishes), but also in invertebrates (drosophilae). The comparison of the triton and trypsin forms of the enzymes permitted to locate centres of regulation in the hydrophobic parts of amphipathetic enzymes (as illustrated by the examples of alkaline phosphatase and gamma-amylase of of the rat and of the drosophila). A considerable variability of the regulatory characteristics of the enzymes under investigation was demonstrated in the different varieties of drosophila. The authors present a hypothesis on the role of the regulatory properties of digestive enzymes in the physiology and the pathology of the digestive and transport systems of the small intestine.
...
PMID:[Regulatory properties of the intestinal enzymes of higher and lower animals as an adaptation mechanism in digestion and absorption]. 48 66

A method is described for the purification of human enterokinase from accumulated duodenal fluid by affinity chromatography using p-aminobenzamidine as the ligand. Resolution was greatest when glycylglycine was substituted as the spacer arm. Purification was not a one-step procedure, and some contamination, principally by the alpha-glucosidases, remained. Their removal was completed by immunoadsorption using antisera raised to enterokinase-free material containing these enzymes, prepared as a by-product of the purification procedure. The final preparation had an activity of 4260 nmol of trypsin/min per mg and was free of other enzymic activity tested. Amino acid and sugar analyses of the highly purified enzyme indicated an acidic glycoprotein containing 57% sugar (neutral sugars 47%, amino sugars 10%). The apparent mol.wts. and Stokes radii of human and pig enterokinase were 296 000 and 316 000, and 5.65 and 5.78 nm respectively. Two isoenzymes were identified for human enterokinase and three for the pig enzyme. Human enterokinase demonstrated a resistance to reduction of disulphide linkages and to sodium dodecyl sulphate binding, which may be related to the need for it to retain its integrity in the digestive environment of the upper small intestine. Antisera to highly purified pig and human enterokinases specifically inhibited enterokinase activity. Immuno-inhibition of intestinal aminopeptidase, maltase and glucoamylase by homologous antisera was not observed.
...
PMID:The purification of human enterokinase by affinity chromatography and immunoadsorption. Some observations on its molecular characteristics and comparisons with the pig enzyme. 94 36

The presence of the enzymatically active allergens equivalent to Der p I (cysteine protease), Der p III (serine protease) and amylase in extracts of Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei was determined using appropriate enzymatic techniques. Biochemical equivalents of all three allergens were present in each extract studied. Studies also showed that the mite extracts contained a variety of other biochemically active enzymes including trypsin, chymotrypsin, carboxypeptidase A and B, glucoamylase and lysozyme. Marked differences in the relative concentrations of some of these enzymes in different mite extracts were observed, particularly trypsin and carboxypeptidase A. The enzymes were physicochemically similar to equivalent enzymes from vertebrate and invertebrate sources. Chromatofocusing studies of faecal extracts derived from D. pteronyssinus and D. farinae showed that several isoforms of each enzyme were present. The data indicated that there were more trypsin isoforms, with pI over a wider range, in extracts prepared from D. pteronyssinus. Proteases and carbohydrases were also found in extracts prepared from faecally enriched material suggesting that they were endoperitrophic and associated with mite digestion. The data suggest that not only are the group I, III and amylase allergens a consistent feature of most pyroglyphid dust mites but also that other proteases and carbohydrases present in mite faeces are allergenic.
...
PMID:A comparative study of allergenic and potentially allergenic enzymes from Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei. 128 68

Intact Giardia muris cysts were subjected to consecutive chloroform/methanol and 2% sodium dodecyl sulfate (SDS) extractions, and to amyloglucosidase treatment. The SDS-insoluble, amyloglucosidase-fast cyst walls (ACW) were further incubated with chymotrypsin, trypsin, papain, or pronase. Low voltage scanning electron microscopy revealed no discernible change in the ultrastructure of the filamentous layer of the cyst wall following any of these treatments. Affinity for cyst wall-specific monoclonal antibody (Meridian Diagnostics, Cincinnati, OH) was also retained after all treatments. Periodic acid-Schiff staining and gas chromatography/mass spectrometry (GC/MS) of intact and treated cyst hydrolysates showed a significant reduction in the amount of glucose associated with the cyst (72 nmoles/10(6) intact cysts vs 1.9 nmoles/10(6) ACW) as a result of amyloglucosidase treatment, indicating that glucose is stored within Giardia as an SDS-insoluble polymer. Galactosamine was identified by GC/MS as the predominant sugar associated with both the ACW and the proteinase treated ACW (42 nmoles/10(6) ACW). High performance liquid chromatographic analysis of amino acids from intact and treated cyst hydrolysates revealed a marked reduction, but not elimination, of detectable quantities of identifiable amino acid residues (255 nmoles/10(6) intact cysts vs 6.8 nmoles/10(6) proteinase treated ACW). These results suggest that the filamentous layer of the cyst wall is primarily a carbohydrate peptide complex.
...
PMID:Carbohydrate and amino acid analyses of Giardia muris cysts. 157 2

The previous findings that the group I and III mite allergens, and amylase present in mite faeces are hydrolytic enzymes has prompted a study to determine whether this material contains other enzymes which could be allergenic. Thus, spent growth medium devoid of whole Dermatophagoides pteronyssinus mites was shown to contain glucoamylase, lipase and lysozyme in addition to the cysteine protease, serine protease and amylase activities associated with the above allergens, respectively. All of these enzymes are probably associated with mite digestive processes. They were rapidly solubilised, heterogeneous with regard to charge (pI in the range 4-8) and demonstrated maximum biochemical activity in the neutral pH range. Three serine proteases were detected and comprised a chymotrypsin-like, a trypsin-like and an unclassified enzyme with pI of 4.1 and 5.3, 8.5 and 7.1, respectively. Only one cysteine protease was observed, which paralleled immunochemically identified Der p I in a variety of assays. It was shown to cleave at lysyl residues and could be inhibited by the specific cysteine protease inhibitor, E-64. The remaining serine proteases, glucoamylase, lipase and lysozyme represent potential allergens.
...
PMID:Faecally derived hydrolytic enzymes from Dermatophagoides pteronyssinus: physicochemical characterisation of potential allergens. 171 11

Full-value diets of similar composition were given to male rats weighing 207-230 g, by intravenous (group 1) or intragastric (group 2) routes. The proportion of amino acids, fats and carbohydrates was 9.9:15.7:74.4 (with regard to their calorific value). The diet calorific value comprised 60.6 kcal/rat/day. An average mass increase in group 1 was 2.44 +/- 0.14 g/day, in group 2 - 1.75 +/- 0.11 g/day. The protein content and activities of alpha- and gamma-amylase, invertase, maltase, and glycil-L-leucine dipeptidase were assayed in the intestinal mucosa of the proximal portion of the small intestine in group 1 rats, while a decreased alpha-amylase activity in the distal portion of the small intestine was recorded in the animals of group 2. The mass of the pancreas in the rats of group 1 and 2 was authentically lower than in the control rats which received oral feeding with natural foods. The lowest mass of the pancreas was observed in the rats of group 1. Specific activity of trypsin, lipase and RNase in the pancreatic tissues of rats in groups 1 and 2 was similar. The results of the study have evidenced a lowered function of the digestive system under conditions of artificial feeding, especially in case of intravenous nutrition.
...
PMID:[Digestive function of the small intestine and pancreas in rats on artificial feeding]. 309 Jul 82

In 849 patients (417 men, 432 women) consecutively hospitalized with acute abdominal pain we compared the value of serum cathodic trypsin-like immunoreactivity, pancreatic lipase (EC 3.2.1.3) and pancreatic isoamylase (EC 3.2.1.1) as diagnostic tests for acute pancreatitis. The diagnoses of acute pancreatitis (in 49 patients, 5.8%) and other diseases were made without knowledge of these enzyme values. When evaluated by means of receiver operating characteristic curves no differences were found in diagnostic performance of the three enzymes. Use of combinations of different enzymes had no advantage over single enzyme determination using discrimination analysis for evaluation. The highest efficiency was for all three enzymes 0.991 (95% confidence limits: 0.983-0.995) and for all three enzymes the discrimination value giving this efficiency was several times the upper limit of reference range: 1 779 micrograms/l for cathodic trypsin-like immunoreactivity, 831 U/l for pancreatic isoamylase and 316 micrograms/l for pancreatic lipase. None of the enzymes had any prognostic value at admission in predicting a mild or severe attack of acute pancreatitis. In conclusion, no single enzyme or combination of enzymes had any diagnostic advantage for acute pancreatitis in patients with acute abdominal pain. Thus selection of one of the three enzymes as diagnostic test of acute pancreatitis is to be based on considerations such as economy, methodological simplicity, possibility of automated assay and the time-consumption at the assay.
...
PMID:Evaluation and comparison of cathodic trypsin-like immunoreactivity, pancreatic lipase and pancreatic isoamylase in the diagnosis of acute pancreatitis in 849 consecutive patients with acute abdominal pain. 371 97

The complete nucleotide sequence of the extracellular glucoamylase gene STA1 from the yeast Saccharomyces diastaticus has been determined. A single open reading frame codes for a 778-amino-acid protein which contains 13 potential N-glycosylation sites. In the 5'- and 3'-flanking regions of the gene, there are striking sequence homologies to the corresponding regions of ADH1 for alcohol dehydrogenase and MAT alpha 2 for mating type control in the yeast Saccharomyces cerevisiae. The putative precursor begins with a hydrophobic segment that presumably acts as a signal sequence for secretion. The presumptive signal sequence showed a significant homology to that of Bacillus subtilis alpha-amylase precursor. The next segment, of ca. 320 amino acids, contains a threonine-rich tract in which direct repeat sequences of 35 amino acids exist, and is bordered by a pair of basic amino acid residues (Lys-Lys) which may be a proteolytic processing signal. The carboxy-terminal half of the precursor is a presumptive glucoamylase which contains several peptide segments showing a high degree of homology with alpha-amylases from widely diverse organisms including a procaryote (B. subtilis) and eucaryotes (Aspergillus oryzae and mouse). Analysis of both the nucleotide sequence of the STA1 gene and the amino acid composition of the purified glucoamylase suggested that the putative precursor is processed to yield subunits H and Y of mature enzyme by both trypsin-like and chymotrypsin-like cleavages.
...
PMID:Nucleotide sequence of the extracellular glucoamylase gene STA1 in the yeast Saccharomyces diastaticus. 391 17


1 2 3 Next >>

---