Showing papers on "Amylase published in 1974"

α-Amylase Measurement of Reducing Groups

Abstract: Publisher Summary This chapter explains α-amylase, which hydrolyses α-14-glucan bonds in polysaccharides, such as starch, amylopectin and glycogen, and their degradation products with a chain length of at least 3 d-glucose residues. Damage to the α-amylase synthesizing tissues, in particular the pancreas, results in leakage of the enzyme from the parenchymal cells and its appearance in the serum. The present findings suggest that the hydrolysis of the polysaccharide chain occurs via the principle of ″multiple attack―, that is, once the enzyme-substrate complex is formed, the enzyme can hydrolyze several bonds of the polymer successively before the enzyme is again liberated in the free form. The amylase activity can be measured by means of the decrease in viscosity of a starch solution, the decrease in turbidity of a starch suspension, the decrease in the intensity of the starch-iodine reaction and the increase in the number of reducing groups. On the basis of the starch-iodine reaction it was concluded that iso-amylases occurred in all five serum fractions as separated by electrophoresis. α-amylase is applied in biochemistry, clinical chemistry and pharmacy.

Purification and Some Properties of Cyclodextrin Glycosyltransferase from a Strain of Bacillus Species

Abstract: An ultracentrifugally homogeneous preparation of the cyclodextrin glycosyltransferase was obtained from the culture broth of a strain of Bacillus species (No. 5 strain) by a purification methods including adsorption on corn starch, ammonium sulfate precipitation, chromatography on DEAE-cellulose column, and gel-filtration on Sephadex G–100. This enzyme preparation (No, 5 enzyme) was separated into two fractions in disc-electrophoresis and Ampholine-electrophoresis (Fr. 1: pI 6.07 and Fr. 2: pI 6.80) which had the ability to form cyclodextrin. These two fractions were similar to each other in the enzymic properties except the isoelectric point. These enzymes differ from the amylase from Bacillus macerans (BMA) in the enzymic properties. Furthermore, No. 5 enzymes differ from BMA in the action on starch. The authors consider that No. 5 enzymes mainly produce the cycloheptaamylose from starch and on the contrary, BMA mainly produces the cyclohexaamylose from starch.

Digestive enzymes secreted by the carnivorous plant Nepenthes macferlanei L.

Abstract: At least two proteases are present in the secretion of the pitchers of Nepenthes macferlanei, a major one with an estimated molecular weight of 59000 and a minor one of 21000. The specificity of the major enzyme, nepenthesin, was broader than previously reported, and strikingly similar to that of pepsin. Lipase activity was also demonstrated, while no amylase activity was present.

Effect of a soybean diet on enzyme content and ultrastructure of the rat exocrine pancreas.

Abstract: The enzyme content and the ultrastructure of the rat exocrine pancreas were studied after feeding a normal diet or diets containing raw (RSF) or heat-inactivated (HSF) soybean flour for 20 days. The w

An Improved Test for the Detection of Salivary Amylase in Stains

Abstract: A method for the detection of saliva stains is described, using an insoluble substrate amylase test. The test has been used to measure the amylase activities of some biological materials apart from saliva, and it is concluded that saliva can be detected in the presence of blood and semen, but that high levels of amylase can occur in faecal stains. A screening test to locate invisble stains is also described.

Effect of elemental diet on pancreatic secretion.

Abstract: Summary Chronic pancreatic fistulas were made in eight mongrel dogs by cannulating the main pancreatic duct. The volume and enzyme content of the pancreatic juice secreted in response to a test meal of either elemental diet or normal diet was measured. No change was found in the concentrations of amylase, lipase, trypsinogen, or protein per unit volume of juice on either diet. However, a 60 per cent reduction in the total volume of flow occurred after elemental diet feeding, resulting in an overall reduction in the total amount of enzymes secreted. The elemental diet has been shown to reduce gastric acid secretion, and this may affect the intestinal phase of pancreatic secretion, thus altering both total volume and enzyme output by the pancreas. A feedback mechanism is suggested.

Pancreatic acinar cells: effects of lanthanum ions on amylase release and calcium ion fluxes

Abstract: 1. The effect of La(3+) on amylase release and Ca(2+) fluxes in mouse pancreatic fragments in vitro was studied.2. Amylase release was increased by 0.1 mM-La(3+) and progressively inhibited by 1.0-10 mM-La(3+). Non-stimulated and bethanecol stimulated secretion were altered in an identical manner. Inhibition of amylase release was rapid and reversible.3. Uptake of (45)Ca(2+) was multiphasic with equilibrium with stable Ca(2+) still not complete after 2 hr. La(3+) (10 mM) limited uptake of (45)Ca(2+) to the extracellular space and slightly decreased total Ca(2+) content. Lower concentrations of La(3+) affected (45)Ca(2+) uptake and total Ca(2+) content in a biphasic manner which paralleled effects on amylase release.4. La(3+) restricted washout of (45)Ca(2+) to isotope in the extracellular space and abolished the bethanecol-stimulated increase in (45)Ca(2+) efflux.5. Uptake of (45)Ca(2+) into intracellular space, as measured by the ;lanthanum' method, was not affected by bethanecol.6. Tissue ultrastructure and Na(+) and K(+) content were not affected by La(3+).7. It is concluded that an influx of extracellular Ca(2+) is not important for triggering of secretion and that La(3+) may inhibit amylase release by acting on the release process rather than on Ca(2+) influx.

Column-Chromatographic Studies of Isoamylases in Human Serum, Urine, and Milk

Abstract: Pancreatic and salivary isoamylases not discerned by a chromatographic method previously described have been detected by a modification of that method. Detailed analysis of the nature of these isoamylases and their distribution showed that the pancreatic type (P-type) and salivary type (S-type) isoamylases in pancreatic extract and saliva appear in normal urine along with an isoamylase of unknown origin (X-type). Normal serum could not be similarly studied because of the low amylase activity in such serum. However, the X-type isoamylase fraction was found in three hyperamylasemic sera, including one from a patient with lung carcinoma who produced S-type amylase. Study of 25 samples of human milk revealed high amylase activity and no detectable P-type; S-type components were found along with the X-type component. Parallel patterns of variation were found in human milk in two patients studied for six months postpartum. Salivary amylase and the S-type amylase in milk and in the serum of the patient with lung carcinoma and marked hyperamylasemia appeared to be similar, and may be identical.

Hormonal and dietary adaptation of rat pancreatic hydrolases before and after weaning

Abstract: All levels of digestive enzymes did not change in constant proportion in the rat pancreas before weaning, and different stimuli were probably responsible for their emergence. The high levels of amylase and chymotrypsinogen observed during the late fetal period were followed by a marked depression in the newborn period. Prompt administration of hydrocortisone prevented the drop of these hydrolases and enhanced the low activity of trypsinogens in 1 to 23 day old pups. This observation together with the reported decreasing activity of the pituitary adrenal axis during the first neonatal weeks suggests that glucocorticoid secretion is a stimulus effective in evoking a series of pancreatic hydrolases. On the other hand, the emergence of lipase was slow, responding poorly to hydrocortisone and to nutritional controls only after 25 days. L Thyroxine, glucagon, or dibutyryl cyclic AMP was unable to increase the specific activities of all hydrolases tested. Nutritional controls were predominant in regulating levels of hydrolases in adult rats. The time course of variation in specific activities of amylase and lipase on high corn oil and high starch diets was unaffected by 7 days of glucagon administration. Adrenalectomy tended to decrease and hydrocortisone treatment tended to increase the level of pancreatic amylase in rats submitted to the same dietary manipulations. The accumulation of amylase required the presence not only of starch but also of protein in the diet.

Virus-induced Pancreatic Disease: Alterations in Concentration of Glucose and Amylase in Blood

Abstract: Infection of mice with coxsackie B viruses resulted in an acinar pancreatitis. Levels of amylase in serum during the acute phase of the infection were elevated as much as 10-fold, and the amylase content of the pancreas was decreased by over 95 %. Histologic examination revealed marked destruction of the acinar cells with little or no effect on the beta cells. Levels of glucose in blood were significantly reduced during the acute infection, but at no time was there evidence of hyperglycemia. In contrast, mice infected with the M variant of encephalomyocarditis virus became markedly hyperglycemic but had only slight elevations of serum amylase levels. These findings are consistent with the earlier observation that encephalomyocarditis virus destroys beta cells but has little effect on acinar cells. Coxsackie B viruses and encephalomyocarditis virus appear to be valuable models for study of the effect of viral infections on the acinar and beta cells of the

Studies on β-Amylase of Bacillus megaterium Strain No. 32

Abstract: An extracellular amylase from a bacterium, Bacillus megaterium strain No, 32, was purified over 2600-fold by precipitation with ammonium sulfate, column chromatography with SE-Sephadex and gel-filtration with Sephadex G–100. The enzyme was most active at pH values around 6.5, and was stable in pH range between 5 and 7.5. The enzyme activity was inhibited by p-chloromercuribenzoate and was restored completely by the addition of cystein. The isoelectric point of the enzyme was pH 9.1. Results of experiments in which maltooligo-saccharides terminated at the reducing end by radioactive glucose were used as substrates for the enzyme, showed that the enzyme removed two glucose unit (maltose) from the nonreducing end. From these results, the enzyme resembled the higher plant β-amylase in the action.

Augmentation of urinary amylase output by excessive diuresis in rats and abolition of this phenomenon by pancreatectomy

Abstract: Effects of diuresis on urinary amylase output were observed in control and pancreatectomized rats on the administration of tap water, glucose and amino acid solution. (1) Urine volume and urinary amylase output were increased as the concentration of glucose solution was increased. Amylase output in the urine revealed a positive correlation with the urine volume. (2) Augmentation of urinary amylase output was also observed in diuretic rats produced by the administration of amino acid solution. (3) Augmentation of urinary amylase output was not found in pancreatectomized rats, although the urine volume was more pronouncedly increased compared to control rats. (4) The urinary amylsae output revealed a positive correlation with the ratio of amylase clearance to creatinine clearance by the kidney in control rats, while the output remained unchanged over relatively wide range of the ratio in pancreatectomized rats. Above evidences indicated that urinary amylase output was significantly augmented by excessive diuresis and that the increased urinary amylase output originated from the pancreas

Examination of Brevibacterium linens by an electrophoretic zymogram technique.

Abstract: SUMMARY: Fifteen isolates of Brevibacterium linens were tested by polyacrylamide gel electrophoresis. Protein patterns and zymograms of 18 intracellular enzyme activities (α-naphthyl acetate and β-naphthyl butyrate esterases, tributyrinase, alcohol-, lactate-, malate-, succinate-, glucose-6-phosphate-, 6-phosphogluconate-, isocitrate-, alanine- and glutamate-dehydrogenases, tetrazolium oxidase, catalase, peroxidase, arylamidase, proteinase and amylase) and four extracellular enzyme activities (α-naphthyl acetate esterase, arylamidase, proteinase and amylase) were examined. Enzyme activities were demonstrated by either specific staining reactions or by the subsequent diffusion of the proteins into a substrate layer. Striking variations of the enzyme patterns occurred among the strains. The variation, however, depended largely on the activity under consideration. Eight different enzymes were selected to calculate a matrix of similarity. The results indicated a separation of the strains into two major subdivisions or biotypes. Only one strain (BLI07) differed markedly from the others.

Chymotrypsinogen in the Intestine of Rats Fed Soybean Trypsin Inhibitor and Its Inability to Suppress Pancreatic Enzyme Secretions

Abstract: Recent investigations have shown that intestinal trypsin and chymotrypsin exert a negative feedback control on pancreatic enzyme secretion in the rat. The present study was conducted to see if soybean trypsin inhibitor ( SBTI ) effected changes in the intestinal activities of these enzymes which could provide an explanation for the pancreatic enzyme response evoked when SBTI is fed to rats. Rats were intubated with either a control diet or diet containing SBTI. One hour after feeding, intestinal contents were removed and washed with either saline or saline containing chicken ovomucoid. Trypsin and amylase activities were determined and chymotrypsin activity was mea sured before and after incubation with trypsin. In control rats, intestinal chymotrypsin activity was not increased by incubation with trypsin. In animals fed SBTI, however, trypsin incubation increased intestinal chymotrypsin activity to 3 to 5 times the preincubation levels. Intestinal trypsin activity of rats fed SBTI was reduced to less than 10% of control values. Continuous infusion of purified bovine chymotrypsin or chymotrypsinogen into rats with a bile-pancreatic juice fistula demonstrated that while chymotrypsin suppressed pancreatic enzyme output, chymotrypsinogen did not. It was concluded, therefore, that SBTI acts to stimulate pancreatic secretion by binding intesti nal trypsin so tightly it cannot fully activate chymotrypsinogen. Since chymotrypsinogen cannot suppress pancreatic secretion, SBTI effectively removes both enzymes from the intestine. An increased pancreatic enzyme secretion is initiated because of loss of the negative feedback regulation normally exerted by the active enzymes. J. Nutr. 104: 105-110, 1974. INDEXING

Eco-physiological studies on Indian arid zone plants

Abstract: Seedlings of Pennisetum typhoides were grown in sodium chloride (NaCl) and gibberellic acid (GA3) separately and in combination, and the effects on the activity of amylase, phosphorylase, aldolase, invertase, hexose-phosphateisomerase, sucrose-synthetase and sucrose-6-phosphate-synthetase were studied. Treatment of the seedlings with NaCl caused an inhibition of the activity of amylase and invertase in the leaf homogenate, but enhanced that of phosphorylase, aldolase, sucrose-synthetase and sucrose-6-phosphate-synthetase. GA3 alone, as observed earlier, promoted the activity of invertase but indicated no significant influence on the other enzymes tested. In combination with salt, however, GA3 tended to counteract, partially or wholly, the effect of NaCl on the activity of several enzymes tested. The possible significance of the similarities between the action of abscisic acid (ABA) and salinity in influencing growth and metabolism of plants during stress is discussed.

Use of Serum Amylase Isoenzymes in Evaluation of Pancreatic Function

Abstract: Amylase isoenzyme patterns were evaluated in serum, urine, and duodenal fluid from 19 patients with cystic fibrosis (CF) and normal subjects. Two thirds of the CF patients with absent pancreatic enzymes lacked a serum pancreatic isoamylase band, while the remainder had a markedly diminished pancreatic band when compared to the salivary isoamylase. In normal sera the pancreatic band is equal to or greater than the salivary band. In all patients with absent enzymes the diagnosis of abnormal pancreatic function could have been made by evaluation of serum isoamylase patterns thereby avoiding duodenal intubation or collection of 72-hour stools for proteolytic enzyme activities. The patients with normal pancreatic enzyme activities had normal serum zymograms. No CF patient had a low total serum amylase concentration. Total duodenal fluid amylase levels may be misleading in the evaluation of pancreatic function since the amylase may be of salivary origin. The advantages of this isoamylase method include (1) simplicity and noninvasiveness, requiring only a small blood sample; (2) specificity for pancreatic function; and (3) independence of pancreatic enzyme medication.