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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mechanisms were studied that might explain the attachment and damage to Candida albicans pseudohyphae by neutrophils in the absence of serum. Attachment of neutrophils to pseudo hyphae was inhibited by Candida mannans (1-10 mg/ml), but not by mannose, dextran, chitin, conconavalin A, or highly charged polyamino acids. Contact was also inhibited by pretreatment of Candida before incubation with neutrophils with chymotrypsin, but not trypsin or several inhibitors of proteases. Similar results were obtained with pretreatment of neutrophils, except that trypsin was inhibitory. When pseudohyphae were killed with ultraviolet light, proteinpolysaccharide complexes of mol wt <10,000 were released which appeared to bind to the surfaces of neutrophils and inhibit contact between neutrophils and Candida, as well as other fungi. Damage to Candida by neutrophils was inhibited by agents known to act on neutrophil oxidative microbicidal mechanisms, including sodium cyanide, sodium azide, catalase, superoxide dismutase, and 1, 4 diazobicyclo (2, 2, 2) octane, a singlet oxygen quencher. Neutrophils from a patient with chronic granulomatous disease did not damage Candida at all. However, the hydroxyl radical scavengers mannitol and benzoate were not inhibitory. Cationic proteins and lactoferrin also did not appear to play a major role in this system. Low concentrations of lysozyme which did not damage Candida in isotonic buffer solutions damaged pseudohyphae in distilled water. Isolated neutrophil granules damaged pseudohyphae only with added hydrogen peroxide and halide, and damage occurred only with granule fractions known to contain myeloperoxidase. These findings suggest that neutrophils recognized a molecule on the Candida surface which has a chymotrypsin sensitive protein component, and which may be liberated from the cell surface upon death of organism. The neutrophil receptors for Candida appear to be sensitive to trypsin and chymotrypsin. Damage to Candida by neutrophils occurred primarily by oxidative mechanisms, including the production of superoxide and hydrogen peroxide interacting with myeloperoxidase and halide, as well as singlet oxygen, but did not appear to involve hydroxyl radical. Lysozyme might have an accessory role, under some conditions.
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PMID:Mechanisms of attachment of neutrophils to Candida albicans pseudohyphae in the absence of serum, and of subsequent damage to pseudohyphae by microbicidal processes of neutrophils in vitro. 34 Apr 71

The effect of trypsin and chymotrypsin on antibacterial factors in bovine colostrum has been studied. Endogenous complement in colostrum was extremely sensitive to both enzymes. IgM was attacked by chymotrypsin but not by trypsin. Trypsin slowly attacked IgG1, causing loss of biological activity due to cleavage of both light and heavy chains. IgG1 was only very slightly attacked by chymotrypsin. Lactoferrin and transferrin in the iron-free state were both susceptible to proteolysis, but the iron saturated forms were more resistant and tended to give rise to stable iron-binding fragments.
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PMID:The effect of trypsin and chymotrypsin on the antibacterial activity of complement, antibodies, and lactoferrin and transferrin in bovine colostrum. 74 24

Lactoferrin, a nonenzyme protein normally secreted in small amounts in pancreatic juice, has been reported by several investigators to be secreted in large amounts in chronic pancreatitis. Whether this increased secretion first occurs at an early or late stage of alcoholic pancreatic disease is unknown. In this study we measured lactoferrin and enzyme outputs in duodenal juice from 10 healthy subjects and three groups of alcoholic subjects: asymptomatic chronic alcoholics without evidence, clinically or biochemically, of pancreatitis (10), those recovered from acute pancreatitis (8), and those with established chronic pancreatitis (8). A multilumen, marker-perfused duodenal catheter was used to aspirate basal pancreatic secretions at the ligament of Treitz. The mean ( +/-SE) lactoferrin concentration in duodenal juice for the four groups of subjects was: healthy, 0.7 +/- 0.1 micrograms/ml; asymptomatic alcoholics, 5.5 +/- 1.5 micrograms/ml; alcoholics who had recovered from acute pancreatitis, 7.4 +/- 0.8 micrograms/ml; and alcoholics with chronic pancreatitis 7.1 +/- 1.9 micrograms/ml. The three groups of alcoholics each had a greater lactoferrin concentration than the normals (P less than 0.005). The output of lactoferrin in the four groups paralleled the concentration in that the three groups of alcoholics had a significantly greater output: healthy subjects, 3.4 +/- 0.5 micrograms/kg/hr; asymptomatic alcoholics, 25.7 +/- 7.4 micrograms/kg/hr; alcoholics recovered from acute pancreatitis, 80.1 +/- 27 micrograms/kg/hr; and alcoholics with chronic pancreatitis, 90.9 +/- 32 micrograms/kg/hr. The output of chymotrypsin and trypsin in the four groups of subjects revealed increased secretory rates in the asymptomatic alcoholics and the alcoholics recovered from acute pancreatitis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lactoferrin secretion in alcoholic pancreatic disease. 333 66

Lactoferrin (LF), chymotrypsin and lipase activity were measured in duodenal juice during pancreatic stimulation. Secretin (0.5 CU/kg/h) plus cerulein (75 ng/kg/h) were infused intravenously in 98 subjects: 33 patients without organic diseases (C), 40 patients affected by chronic pancreatitis (CP), and 25 patients with different gastrointestinal diseases (GID). LF was determined by means of a new noncompetitive immunoenzymatic assay with a sensitivity in the duodenal juice of 5 ng/ml. Duodenal LF concentrations were significantly higher in CP than in C or GID (p less than 0.001). LF was in a normal range in acute relapsing pancreatitis due to biliary stones or pancreas divisum. In the diagnosis of the chronic pancreatitis, LF/lipase ratios showed a specificity of 93% and a sensitivity of 95%. Our results show that LF immunoassay in duodenal juice is a sensitive and accurate assay to apply in pancreatic function tests involving duodenal content analysis.
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PMID:Duodenal lactoferrin in patients with chronic pancreatitis and gastrointestinal diseases. 406 44

The susceptibility of lactoferrin in bovine colostrum and human milk to digestion by trypsin and chymotrypsin has been investigated. Neither enzyme had much effect on the lactoferrin-mediated antimicrobial activity of human milk, and the iron binding capacity of lactoferrin in the milk was only slightly reduced. Likewise both enzymes had only a slight effect on the iron-binding capacity of purified lactoferrin. Although iron-free (apo)lactoferrin was slightly more susceptible to digestion, especially by chymotrypsin, than the iron-saturated form, the difference was much less than has been found in earlier studies with other proteins of the transferrin class. In contrast, trypsin destroyed the antimicrobial activity of bovine colostrum, and, in line with earlier studies, appreciably reduced the iron-binding capacity of both colostrum and purified bovine apolactoferrin. Bovine iron-saturated lactoferrin was more resistant to digestion. The unusual resistance of human apolactoferrin to proteolysis may reflect an evolutionary development designed to permit its survival in the gut of the infant.
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PMID:The effect of trypsin and chymotrypsin on the in vitro antimicrobial and iron-binding properties of lactoferrin in human milk and bovine colostrum. Unusual resistance of human apolactoferrin to proteolytic digestion. 634 99

The presence of neutrophils within the lung is a characteristic feature of a variety of lung diseases. To evaluate the potential role of alveolar macrophages in modulating the migration of neutrophils to the lung, normal human alveolar macrophages obtained from volunteers by bronchopulmonary lavage, were exposed for various periods of time in vitro to heat-killed microorganisms, and noninfectious particulates, immune complexes, and the macrophage supernates were evaluated for chemotactic activity. The microorganisms, noninfectious particulates, and immune complexes were chosen as stimuli for alveolar macrophages because these stimuli are representative of a spectrum of pathogenic agents that cause neutrophil accumulation in the lower respiratory tract. After incubation with each of these stimuli, alveolar macrophages released low molecular weight (400-600) chemotactic factor(s) (alveolar macrophage-derived chemotactic factor[s] [AMCF]) with relatively more activity for neutrophils than monocytes or eosinophils. Checker-board analysis of the AMCF revealed that the factor was primarily chemotactic and not chemokinetic for neutrophils. The selectivity for neutrophils vs. monocytes could not be explained by a selective deactivation of monocytes, because the AMCF was more potent in deactivating neutrophils than monocytes. Partial characterization of AMCF demonstrated it was heterogeneous with the following features: (a) stable to heating at 56 and 100 degrees C for 30 min; (b) stable over a pH range of 1.0 to 12.0 for 60 min; (c) stable after exposure to trypsin, papain, chymotrypsin, collagenase, and elastase; (d) partially inhibited by serum chemotactic factor inhibitor(s); (e) two major isoelectric points (pI 7.6 and 5.2); and (f) partially extractable into ethyl acetate, ether, and hexane. Although AMCF was, at least, partially lipid in nature, it did not appear to be similar to previously described lipid chemotactic factors (e.g., hydroxy-derivatives of 5,8,10,14-eicosatetraenoic acid); analysis by gas chromatography-mass spectrophotometry of AMCF extracted into ethyl acetate did not reveal the presence of 5,8,10,14-eicosatetraenoic acid. The macrophage supernates containing the AMCF also stimulated normal human neutrophils to release lysozyme and lactoferrin but not lactate dehydrogenase. These studies suggest that a wide variety of potentially pathogenic stimuli induce normal alveolar macrophages to generate a low molecular weight chemotactic factor(s) that preferentially attracts neutrophils. Because alveolar macrophages are normal residents of alveoli, it is likely that by releasing this factor(s) macrophages play a significant role in amplifying the inflammatory processes seen in many acute and chronic lung diseases.
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PMID:Human alveolar macrophage-derived chemotactic factor for neutrophils. Stimuli and partial characterization. 699 85

Laboratory tests are the object of continuous interest in acute as well as chronic pancreatic disease. Enzymic assays play an important role, particularly in screening for pancreatic disease. The diagnostic contribution of amylase, isoamylases, immunoreactive trypsin and lactoferrin, ribonuclease and galactosyltransferase, as well as the problem of chronic nonpancreatic hyperamylasemia is reviewed. Functional methods detect a normal or abnormal function and in this sense the results should be interpreted. Present evaluation of the pancreozymin-secretin test, the Lundh test, fecal chymotrypsin, determination of stimulated chymotrypsin secretion by peroral synthetic substrates marked with 4-aminobenzoic acid, duodenal excretion of 75Se-methionine and plasma pancreatic polypeptide is given. Up to now, immunologic methods have not fulfilled the expectations in spite of considerable attention paid to them in recent years.
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PMID:[Developments in the laboratory diagnosis of diseases of the exocrine pancreas (author's transl)]. 702 8

Naturally occurring anti-band 3 antibodies were affinity purified from pooled human IgG (Sandoglobulin) (Lutz, H. U., Flepp, R., and Stringaro-Wipf, G. (1984) J. Immunol. 133, 2610-2618). They bound to the major integral membrane protein of human red blood cells and its 55-kDa NH2-terminal chymotryptic fragment but not to the carbohydrate-rich 38-kDa fragment on blots. Likewise, neither an endo-beta-galactosidase nor a neuraminidase treatment of band 3 on intact red cells reduced their binding to the blotted antigen. Lactoferrin (10 micrograms/ml) had no significant effect on their binding to band 3 and to its 55-kDa chymotryptic fragment. Even in the presence of 20 micrograms/ml lactoferrin anti-band 3 antibodies bound specifically to chymotrypsin-pretreated and oxidatively stressed red cells. Thus, naturally occurring anti-band 3 antibodies bind to protein rather than carbohydrate within band 3 protein, irrespectively of whether the antibodies were depleted of anti-idiotypic and other IgG-reactive antibodies or not.
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PMID:Naturally occurring anti-band 3 antibodies bind to protein rather than to carbohydrate on band 3. 769 90

Bovine lactoferrin binds to a 60 kDa heat shock protein of Helicobacter pylori. Binding ability was related to human immunoglobulin G because bovine lactoferrin binding proteins were isolated by extraction of cell surface associated proteins with distilled water, applied on IgG-Sepharose and nickel sulphate chelate affinity chromatography. Binding was demonstrated by Western blot after purified protein was digested with alpha-chymotrypsin and incubated with peroxidase-labeled bovine lactoferrin. Binding was inhibited by bovine lactoferrin, lactose, rhamnose, galactose, and two iron-containing proteins, ferritin and haptoglobin. Helicobacter pylori binds ferritin and haptoglobin via charge or hydrophobic interactions because this binding was not inhibited by specific and various glycoproteins or carbohydrates. Carbohydrate moieties of bovine lactoferrin molecules seem to be involved in binding because glycoproteins with similar carbohydrate structures strongly inhibited binding. Scatchard plot analysis of the binding of peroxidase-labeled bovine lactoferrin to H. pylori cells yielded a kd 2.88 x 10(-6) M. In addition, binding of H. pylori cells to bovine lactoferrin was enhanced when bacteria treated with pepsin or alpha-chymotrypsin after isolation from iron-restricted and iron-containing media.
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PMID:Cryptic domains of a 60 kDa heat shock protein of Helicobacter pylori bound to bovine lactoferrin. 911 43

Lactoferrin is an iron binding glycoprotein with a molecular weight of 80 kDa. The molecule is divided into two lobes representing the N-terminal and C-terminal halves of the polypeptide chain, each containing an iron binding site. The serine proteinases such as trypsin, chymotrypsin, and pepsin hydrolyze lactoferrin into two unequal halves while proteinase K divides this protein into two equal halves. In the first step of hydrolysis by proteinase K, the C- and N-lobes, each having a molecular weight of approximately 40 kDa, are generated. In the next step, the lobes are further hydrolyzed into small molecular weight peptides. The proteinase K isolated from the hydrolyzed product does not show enzymatic activity suggesting that the enzyme is inhibited. Furthermore, the hydrolysis experiments on N-lobe and C-lobe showed that the inhibitory fragment came from the C-lobe. The purified lactoferrin fragment was found to be a decapeptide with an amino acid sequence of H2N-Val-Ala-Gln-Gly-Ala-Ala-Gly-Leu-Ala-COOH. The complex formed between proteinase K and lactoferrin fragment was crystallized by microdialysis. The crystals belonged to the monoclinic space group P2(1) with cell dimensions a = 44.4 A, b = 38.6 A, c = 79.2 A, beta = 105.8 degrees and Z = 2. The crystal structure has been determined at 2.4 A resolution. It has been refined to an R factor of 0.163 for 9044 reflections. The Lf-fragment forms several intermolecular interactions with proteinase K. The Ser-224 Ogamma and His-57 N epsilon2 move away to a distance of 3.68 A in the complex. In the crystal structure, Gln-3I (I indicates inhibitor i.e., lactoferrin fragment) is involved in a direct intermolecular interaction with a symmetry related proteinase K molecule through a strong hydrogen bond with Asp-254. The mode of intermolecular interactions in the complex conformational features of the enzyme and placement of the fragment with respect to the enzyme resemble with the molecular complex of proteinase K with its natural inhibitor PKI3 from wheat.
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PMID:Crystal structure of a complex formed between proteolytically-generated lactoferrin fragment and proteinase K. 974 42


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