Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study demonstrates that a serine endopeptidase of pancreatic origin (elastase 2) circulates in human blood. A specific and highly sensitive radioimmunoassay has been developed for pancreatic elastase 2 in human serum. The inactivation of elastase 2 employed as radioiodinated tracer with an active site-specific reagent (phenylmethanesulfonyl fluoride) was necessary to prevent its binding by serum alpha1-antitrypsin and alpha2-macroglobulin while maintaining its immunoreactivity. The assay is based upon competition of standard human pancreatic elastase 2 with 125I-labeled phenylmethanesulfonyl elastase 2 for specific antibody binding sites, after which a second antibody precipitation step is used to separate bound from free 125I-labeled phenylmethanesulfonyl elastase 2. The minimum detectable concentration of elastase 2 was 0.9 ng/ml. The average normal fasting serum level determined was 71 ng/ml, approximately 80-fold greater than the minimum detectable amount. The form of radioimmunoassayable elastase 2 in normal human serum has been investigated by gel filtration of serum samples on Sephadex G-200 followed by radioimmunoassay of column fractions. The majority of the immunoreactive elastase 2 is eluted from G-200 in the void volume. While a minor amount of elastase 2 is eluted in a position consistent with alpha1-antitrypsin-elastase 2 complex, no free elastase or free proelastase is detectable. Addition of exogenous elastase 2 to normal serum prior to gel filtration on G-200 produced an increase only in the peak of radioimmunoassayable elastase bound to alpha1-antitrypsin. In vitro experiments have demonstrated that while elastase 2 bound to alpha1-antitrypsin is immunologically reactive, alpha2-macroglobulin-bound elastase 2 cross-reacts less than 2% in this radioimmunoassay. The assay has been shown to be specific for elastase 2. Human pancreatic elastase 1, anionic trypsin, chymotrypsin I, and chymotrypsin II do not cross-react in this assay system. The major advantages of this radioimmunoassay over enzymatic assays are its high sensitivity and ability to measure the enzyme in terms of its total protein concentration.
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PMID:Pancreatic elastase in human serum. Determination by radioimmunoassay. 83 29

This paper reviews recent developments of analytical methods for the determination of alpha-amylase, of its isoenzymes, and of lipase. The evaluation of severity and etiology of acute pancreatitis by enzyme assays, e.g., pancreatic elastase 1, phospholipase A2, and routine enzymes are discussed. The limited significance of enzyme determinations as compared to imaging and endoscopic procedures for the diagnosis of chronic pancreatitis is demonstrated. Indirect "tubeless" tests for the evaluation of pancreatic exocrine insufficiency with respect to the secretion of chymotrypsin (chymotrypsin in stool and NBT-PABA test) and cholesterol esterase (pancreolauryl test) are reviewed. Finally, the superiority of morphologic investigations over biochemical tests for the timely detection of pancreatic carcinoma is shown.
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PMID:Advances in the enzyme diagnosis of pancreatic diseases. 225 33

Incubation of human serum alpha 1-antichymotrypsin with human pancreatic elastase 2 or porcine pancreatic elastase results in the complete inhibition of each enzyme as determined by spectrophotometric assays. alpha 1-Antichymotrypsin reacts much more rapidly with the human than with the porcine enzyme. The inhibitor: enzyme molar ratio, required to obtain full inhibition of enzymatic activity, is equal to 1.25/1 when alpha 1-antichymotrypsin reacts with human pancreatic elastase 2 while it is markedly higher with porcine pancreatic elastase (5.5/1). Patterns obtained by SDS/polyacrylamide gel electrophoresis of the reaction products show the formation with both enzymes of an equimolar complex (Mr near 77 000) and the release of a fragment migrating as a peptide of Mr near 5000. Moreover a free proteolytically modified form of alpha 1-antichymotrypsin, electrophoretically identical with that obtained in the reaction with cathepsin G or bovine chymotrypsin, is produced in the reaction with each elastase but in a much greater amount when alpha 1-antichymotrypsin reacts with porcine elastase than with human elastase. As a consequence of our findings, the specificity of alpha 1-antichymotrypsin, so far limited to the inhibition of chymotrypsin-like enzymes from pancreas and leukocyte origin, has to be extended to the two pancreatic elastases investigated in this work. A contribution of alpha 1-antichymotrypsin to the regulatory balance between plasma inhibitors and human pancreatic elastase 2 in pancreatic diseases is suggested.
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PMID:Human serum alpha 1-antichymotrypsin is an inhibitor of pancreatic elastases. 384 29

The total daily amount of extractable cationic trypsin, chymotrypsin, and pancreatic elastase 2 in feces and ileostomy fluids has been studied in normal individuals and healthy colectomized subjects. Quantitation was performed using immunological assays with polyethylene glycol as a fecal marker. The extractable amount of each of these enzymes in the feces of normal individuals was less than 1 mg/24 h. However, in fecal extracts from antibiotic-treated normal individuals a 100-fold increase in immunoreactive cationic trypsin was observed, while chymotrypsin and elastase 2 were only 2- to 3-fold higher. In extracts from ileostomy fluids cationic trypsin, elastase, and chymotrypsin all showed mean values in the order of 50-200 mg/24 h. The characterization of the immunoreactivity of pancreatic proteases showed no qualitative differences when measured in duodenal juice or fecal and ileostomy extracts.
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PMID:Determination of immunoreactive trypsin, pancreatic elastase and chymotrypsin in extracts of human feces and ileostomy drainage. 655 6

The substrate specificity of human pancreatic elastase 2 was investigated by using a series of peptide p-nitroanilides. The kinetic constants, kcat and Km, for the hydrolysis of these peptides revealed that this serine protease preferentially hydrolyzes peptides containing P1 amino acids which have medium to large hydrophobic side chains, except for those which are disubstituted on the first carbon of the side chain. Thus, human pancreatic elastase 2 appears to be similar in peptide bond specificity to the recently described porcine pancreatic elastase 2 [Gertler, A., Weiss, Y., & Burstein, Y. (1977) Biochemistry 16, 2709] but differs significantly in specificity from porcine elastase 1. The best substrates for human pancreatic elastase 2 were glutaryl-Ala-Ala-Pro-Leu-p nitroanilide and succinyl-Ala-Ala-Pro-Met-p-nitroanilide. However, there was little difference among substrates with leucine, methionine, phenylalanine, tyrosine, norvaline, or norleucine in the P1 position. Changes in the hydrolysis rate of peptides with differing P5 residues indicate that this enzyme has an extended binding site which interacts with at least five residues of peptide substrates. The overall catalytic efficiency of human pancreatic elastase 2 is significantly lower than that of porcine elastase 1 or bovine chymotrypsin with the compounds studied.
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PMID:Substrate specificity of human pancreatic elastase 2. 689 42

The determination of faecal pancreatic elastase 1 is a reliable test for the diagnosis of chronic pancreatic diseases in man due to its high sensitivity and specificity (93%). A clinical study was performed to investigate the detectability of canine faecal pancreatic elastase with polyclonal anti human pancreatic elastase 1 antibodies in 52 dogs with chronic diarrhoea and weight loss. To assess the diagnostic value of this parameter for the diagnosis of exocrine pancreatic insufficiency (EPI) in dogs faecal chymotrypsin activity was determined and serum trypsin-like immunoreactivity (TLI) concentration was measured within the Ceruletid test in all patients. The study revealed that canine faecal pancreatic elastase cross reacts with polyclonal anti human pancreatic elastase 1 antibodies. In comparison with the results of the other pancreas tests it was proved that the concentration of canine faecal pancreatic elastase determined by rocket immunoelectrophoresis is highly sensitive for EPI in dogs (sensitivity 100%) but there are species differences in specificity between man and dog (specificity 56.5%).
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PMID:[Determination and clinical relevance of fecal pancreatic elastase in dogs]. 993 98