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At least 19 recordsLinked to original sources
PubMed1998

Wider distribution of salivary-type isoamylase activity as compared with pancreatic-type isoamylase activity in serum: a study on young female adults.

The clinical implications of a wider distribution of salivary type (S-type) isoamylase activity, as compared with that of pancreatic type (P-type) isoamylase activity in the serum of young female adults of 18-23 years old was studied. A high correlation existed between the S-type isoamylase levels in the initial determination and those in the second determination one year after on the same subjects, indicating that the wider distribution of S-type isoamylase level reflects an individual variation. The serum level of S-type isoamylase was highly correlated with the S-type isoamylase activity in saliva. Among the additional factors studied, a weak positive correlation was present between energy intake and the total and S-type isoamylase activities in serum. However, there was no negative correlation between the S-type isoamylase level and body mass index (BMI), which was reported for young male adults.

Adolescent↗
PubMed1990

Nucleotide sequence and expression of the isoamylase gene from an isoamylase-hyperproducing mutant, Pseudomonas amyloderamosa JD210.

The isoamylase gene (ISO) of Pseudomonas amyloderamosa JD210, an isoamylase-hyperproducing mutant, was cloned in an isoamylase-deficient and transformable mutant strain K31. By deletion analysis, the ISO gene was found to be located within a 3.3 kilobases BamHI fragment. Its nucleotide sequence contained an open reading frame of 2328 nucleotides (776 amino acids) encoding a secreted isoamylase precursor. The ISO gene fragment was inserted into plasmids pKT230 and pBR 322 in opposite orientations. The expression of the ISO gene in the constructed plasmids was compared in P. amyloderamosa K31, Pseudomonas aeruginosa PAO1-161, Pseudomonas putida mt-2 and Escherichia coli HB101. In all transformed cells, the majority of the isoamylase produced was secreted and higher isoamylase activities were obtained in transformats with the transcriptional direction of the ISO gene similar to the nearby drug-determinant gene of the vector.

Amino Acid Sequence↗
PubMed1979

Changes in serum isoamylase activities after fibergastroduodenoscopy and colonoscopy. Isoamylase after FGDS and FCS.

The effects of endoscopic examination on the changes in serum amylase activity were investigated in hospitalized patients without salivary and pancreatic disorders. Sixty-nine patients were selected for the peroral fibergastroduodenal endoscopy and twenty-three patients for the peranal fibercolonoscopy. Blood samples were drawn before, immediately after, 4 hrs and 24 hrs after the termination of the examinations. The serum activities of the salivary type isoamylase increased in 7 out of 69 cases 4 hrs after the examination with the fibergastroduodenoscope, but none in all 23 cases after the examination with the fibercolonoscope. On the other hand, the serum activity of the pancreatic type isoamylase did not change following both examinations. A significant rise in serum cortisol levels was induced by both examinations. There were no correlations between the rise in salivary type isoamylase and that in serum cortisol levels. These results did not suggest that the increase of salivary type isoamylase was mediated by the hypophysio-adrenocortical axis. Other possible mechanisms were discussed.

Colon↗
PubMed1999

Purification, characterization, and cDNA structure of isoamylase from developing endosperm of rice.

Isoamylase (EC 3.2.1.68) in rice (Oryza sativa L.) was efficiently purified within a day to homogeneity, as confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), from developing endosperm by sequential use of Q Sepharose HP anion-exchange chromatography, ammonium sulfate fractionation, and TSKgel G4000SWXL and G3000SWXL gel filtration chromatography. Although the protein exhibited a molecular size of ca. 83 kDa on SDS-PAGE, the apparent size of the native enzyme was approximately 340 and 490 kDa on TSKgel G3000SWXL and G4000SWXL gel filtration chromatograms, respectively, suggesting that rice isoamylase exists in a homo-tetramer to homo-hexamer form in developing endosperm. The purified rice isoamylase was able to debranch glycogen, phytoglycogen and amylopectin but could not attack pullulan. The optimum pH and temperature for isoamylase activity were found to be pH 6.5 to 7.0 and 30 degrees C, respectively. The enzyme activity was completely inhibited by HgCl2 and p-chloromercuribenzoate at 1 mM. These results indicate that rice isoamylase possesses properties which are distinct from those reported for bacterial isoamylase. Complementary-DNA clones for rice endosperm isoamylase were isolated with a polymerase-chain-reaction product as probe which was generated by primers designed from nucleotides conserved in cDNA for maize Sugary-1 isoamylase (M.G. James et al., 1995. Plant Cell 7: 417-429) and a Pseudomonas amyloderamosa gene encoding isoamylase (A. Amemura et al. 1988, J Biol Chem 263: 9271-9275). The nucleotide sequence and deduced amino acid sequence of the longest clone showed a high similarity to those of maize Surgary-1 isoamylase, but a lesser similarity to those of Pseudomonas amyloderamosa isoamylase. Southern blot analysis and gene mapping analysis indicated that the isoamylase gene exists as a single copy in the rice genome and is located on chromosome 8 of cv. Nipponbare which belongs to the Japonica rice group. Phylogenetic analysis indicated that isoamylases from maize and rice are more closely related to a number of glgX gene products of the blue green alga Synechocystis and various bacteria than to isoamylases from Pseudomonas and Flavobacterium. Hence, it is proposed that glgX proteins are classified as isoamylase-type debranching enzymes. Our tree also showed that all starch- and glycogen-debranching enzymes from plants and bacteria tested can be classified into two distinct types, an isoamylase-type and a pullulanase-type.

Amino Acid Sequence↗
PubMed1991

Fecal isoamylase activity in patients with pancreatic diseases.

Fecal isoamylase activity was studied in 93 consecutive patients (26 in the recovery stage of acute pancreatitis, 24 with chronic pancreatitis, 13 with pancreatic cancer, and 30 with other gastrointestinal diseases) and compared with fecal chymotrypsin activity and the results of the secretin test. Seventy-six healthy subjects were studied as controls. Both pancreatic (p)-type and salivary (s)-type isoamylase activities in stool were determined by inhibitor assay as well as cellulose acetate electrophoresis. The mean fecal amylase activity in healthy subjects was 757 +/- 88 IU/g (p-type isoamylase: 77 +/- 2%, s-type isoamylase: 23 +/- 2%). There was a good correlation between fecal p-type isoamylase and chymotrypsin activities (r = 0.625, p less than 0.001). Fecal p-type isoamylase activity in patients with chronic pancreatitis and pancreatic cancer was significantly lower than in healthy subjects (p less than 0.001). Patients with moderate and severe exocrine pancreatic insufficiency as determined by the secretin test had significantly lower fecal p-type isoamylase activity. Daily fat intake did not affect fecal amylase or isoamylase activities. Fecal s-type isoamylase activity in patients with hypoacidity was significantly higher than in patients with hyperacidity, but no difference in fecal p-type isoamylase activity was observed. It is concluded that analysis of fecal isoamylase activity is useful in the assessment of pancreatic function.

Acute Disease↗
PubMed1985

Serum amylase and isoamylases and their origins in healthy dogs and dogs with experimentally induced acute pancreatitis.

Agarose-gel electrophoresis was used to study isoamylases in tissues and sera of healthy dogs and the sera of dogs with experimentally induced acute pancreatitis. Three or 4 isoamylases were found in the serum of healthy dogs; they were numbered 1 to 4 with respect to their degree of anodal migration. Peak 4 isoamylase, the slowest migrating (most cathodal), was the major isoamylase fraction in sera and tissues of healthy dogs. Peak 3 was identified as a pancreas-specific isoamylase. Absolute total serum amylase and total isoamylase concentrations increased significantly in dogs with pancreatitis compared with values for control dogs (sham-operated). The relative increase in peak 3 isoamylase was greater than that seen with total amylase or the other isoamylases. The decrease in total serum amylase and isoamylase concentrations paralleled each other; however, peak 3 remained proportionally high longer than did total amylase and the other isoamylase fractions. These findings indicate that measurement of peak 3 isoamylase concentrations may be of diagnostic value in dogs with suspected pancreatitis with normoamylasemia and in dogs with extrapancreatic hyperamylasemia.

Acute Disease↗
PubMed1976

Isoamylases in blood, urine, and tissue homogenates from some experimental mammals.

The isoamylase patterns of the serum, urine, and various tissue extracts of some mammalian species were studied with the aid of agarose gel electrophoresis followed by incubation with a starch-dye polymer. In the dog and cat mainly one fraction of amylase, derived from the pancreatic gland, was found in the serum and in the urine. In the rabbit, identical isoamylases were produced by the salivary and pancreatic glands and possibly also by the duodenum; they were detectable in serum and were excreted in the urine in partly changed form. In the rat, the salivary isoamylase was clearly differentiated from the pancreatic isoamylases in serum and urine. Skeletal muscle also produced a starch-degrading enzyme, but no conclusive evidence of hepatic amylase production was found. In the mouse, the salivary and pancreatic isoamylases of serum and urine were clearly separated. Evidence of amylase production was found in the liver and duodenum. These amylases belonged to the pancreatic group of isoamylases. In the guinea-pig, the salivary and pancreatic isoamylases differed from one another in their electrophoretic migration rates; in the serum and urine only salivary isoamylases were detectable. In the Golden Syrian hamster, the salivary glands, the pancreatic glands, and the small intestine-fallopian tube differed from each other in respect of the groups of isoamylases they produced. The pancreatic isoamylase was never seen in the serum or the urine.

Animals↗
PubMed1976

Amylases of the genital tract. I. Isoamylases of genital tract tissue homogenates and peritoneal fluid.

Homogenates of tissue from the female genital tract contain isoamylases which are, to a certain extent, electrophoretically distinguishable from the pancreatic and salivary isoamylases. In healthy nonpregnant women, high levels of activity of genital isoamylases were found in tissue homogenates of cervical and Fallopian tube mucosa, whereas activity was weak or absent in homogenates of endometrium. The isoamylases of the cervical mucosa had an electrophoretic migration rate toward the anode identical to that of the salivary main fraction, whereas the isoamylases of the Fallopian tube migrated faster. Specific genital isoamylase activities were also demonstrable in peritoneal fluid collected from the cul-de-sac. During the menstrual cycle, these activities showed a midcycle peak. In pregnant women, the levels of activity of the genital isoamylases in peritoneal fluid were lower than in nonpregnant women. In homogenates of the male accessory genital glands, the isoamylases specific for the genital tract were present in minute amounts. The isoamylases specific for the genital tract were not detectable in serum in either sex.

Adult↗
PubMed1984

Metabolism of human isoamylases in the rabbit.

Human isoamylases were purified from pancreas and saliva with separation of salivary isoenzymes into glycosylated and nonglycosylated forms. After iodination, bolus injection of each purified isoamylase into conscious rabbits revealed biexponential disappearance from plasma. Glycosylated salivary amylase had a metabolic clearance (t 1/2 = 35 min) that was three to four times faster than nonglycosylated salivary (t 1/2 = 139 min) or pancreatic (t 1/2 = 111 min) amylase. In contrast to our previous studies on homologous (rabbit) isoamylases, human pancreatic isoamylase was excreted into urine as protein-bound radioactivity more readily than salivary isoamylase. No organ contained more than 18% of the injected dose of radioactivity except for a striking accumulation of radioactivity in the liver after injection of 125I-labeled glycosylated salivary amylase. We concluded that 1) human nonglycosylated salivary amylase and pancreatic amylase are cleared from the rabbit circulation at rates comparable with those reported for homologous isoamylases in the rabbit and baboon, 2) the rabbit kidney excretes human pancreatic amylase into urine more readily than human salivary isoamylases, and 3) with the notable exception of glycosylated salivary isoamylase, human isoamylases do not appear to be metabolized primarily by any single organ.

Animals↗
PubMed1982

Diagnostic value of routine isoamylase assay of hyperamylasemic serum.

The purpose of this study was to determine if routine isoamylase assay would provide valuable diagnostic information in patients with hyperamylasemia. Isoamylase distribution was determined in sera of 37 consecutive hyperamylasemic patients. The attending physicians (without knowledge of the isoamylase level) had considered acute pancreatitis to be "probable" in 19, "possible" in 4, and "unlikely" in 14 of these 37 patients. Three of the patients considered probably to have pancreatitis and 3 thought possibly to have pancreatitis had normal serum pancreatic isoamylase levels. Knowledge of the normal pancreatic isoamylase level in these 6 patients probably would have changed the clinical diagnosis to some condition other than pancreatitis. Of the 14 hyperamylasemic patients thought "unlikely" to have pancreatitis, 7 had an elevation of just pancreatic isoamylase and 3 additional patients had elevation of both pancreatic and salivary isoamylases. It seems likely that knowledge of these elevated pancreatic isoamylase levels would have changed the clinical diagnosis to "probable" pancreatitis for many of these patients. We conclude that routine isoamylase assay provides diagnostic information that might change the clinical diagnosis in 20%--40% of hyperamylasemic patients.

Acute Disease↗
PubMed1984

Comparison of serum amylase pancreatic isoamylase and lipase in patients with hyperamylasemia.

We compared results of measurements of total serum amylase, pancreatic isoamylase, and lipase measurements in patients with hyperamylasemia. Serial measurements of these three enzyme levels in patients recovering from acute pancreatitis indicated that pancreatic isoamylase and lipase were elevated above normal to a greater extent and remained elevated much longer than did the total amylase. This finding indicates an appreciable sensitivity advantage of the pancreatic isoamylase and lipase over total amylase measurement during the recovery phase of pancreatitis. Comparison of pancreatic isoamylase and lipase levels in selected sera indicated a good correlation (r = 0.84) between these two measurements in patients who did not have macroamylasemia. Lipase was normal in sera with amylase elevations due solely to salivary isoamylase. Thus, in nonmacroamylsemic sera, pancreatic isoamylase and lipase appear to be roughly interchangeable markers of the level of pancreatic enzymes in the blood. An advantage of the lipase assay is that this enzyme is normal in hyperamylasemia caused by macroamylasemia, whereas the inhibitor assay indicates that the pancreatic isoamylase is elevated. Development of automated assays for either pancreatic isoamylase or lipase should lead to the routine use of one of these assays in place of the present reliance on total amylase measurements in the diagnosis of pancreatitis.

Acute Disease↗
PubMed1997

An isoamylase with neutral pH optimum from a Flavobacterium species: cloning, characterization and expression of the iam gene.

The gene encoding an isoamylase with neutral pH optimum (iam) from a Flavobacterium species was cloned using a PCR probe generated from highly conserved regions of amylolytic enzymes. Active isoamylase was expressed from a 4.9-kb Pst I fragment in Escherichia coli, and was detected in the extracellular medium by a plate assay. The iam nucleotide sequence has an open reading frame of 2334 nucleotides (778 amino acids) with a GC content of 69%. Sequence analysis suggests that transcriptional control of the Flavobacterium sp. iam gene is mediated through the product of a malT regulatory gene. The deduced amino acid sequence of iam contained an N-terminal signal peptide of 32 amino acids, and was 61% homologous with Pseudomonas amyloderamosa isoamylase. The mature enzyme, which was engineered for overexpression in E. coli and purified to homogeneity, has a relative molecular mass of 83 kDa, a pH optimum of 6-7, and a highest rate of hydrolysis for glycogen (but did not cleave pullulan). Polyclonal antiserum generated from purified donor isoamylase cross-reacted with crude and purified recombinant isoamylase from E. coli. This is the first report of the cloning, characterization, and sequence of an novel isoamylase that has a neutral pH optimum. A comparison of the sequence of Flavobacterium sp. iam with acidic isoamylase from Pseudomonas sp. identified putative residues which may be associated with the pH for optimal activity of isoamylases.

Amino Acid Sequence↗
PubMed1976

Serum isoamylases in cystic fibrosis.

Salivary and pancreatic isoamylases were determined in the sera of 33 patients with cystic fibrosis (CF) and in 34 CF-parents. Pancreatic serum isoamylase activities were greatly decreased in patients with CF, and only two values from this group fell within the normal range. Salvary isoamylases, however, were markedly increased so that the total serum amylase activities were normal. We interpret the low pancreatic isoamylase levels in serum to reflect reduced exocrine masses in the pancreas of CF-children. In heterozygotes, the mean activity of the pancreatic isoamylase was significantly higher than in the reference group, while salivary isoamylases were within the normal range. Due to a genetic polymorphism pancreatic isoamylase may occur in two main fractions. This variant type of pancreatic isoamylase appeared more frequently in CF-heterozygotes than was expected from a reference group of blood donors.

Adolescent↗
PubMed2003

The sugary-type isoamylase gene from rice and Aegilops tauschii: characterization and comparison with maize and arabidopsis.

Genes for an isoamylase-like debranching enzyme have been isolated from rice and Aegilops tauschii, the donor of the D genome to wheat. The structures of the genes are very similar to each other and to the maize SU1 isoamylase gene and consist of 18 exons spread over approximately 7.5 kb. Southern analysis and fluorescent in situ hybridization showed the Ae. tauschii gene to be located in the proximal region of the short arm of chromosome 7D, thus showing synteny with the localization of the rice isoamylase gene on rice chromosome 8. Analysis of the expression pattern of wheat sugary isoamylase genes indicates that they are strongly expressed in the developing endosperm 6 days after flowering. Three distinct Sugary-type cDNA sequences were isolated from the wheat endosperm that are likely to correspond to the products of the three genomes. The deduced amino acid sequence of rice and wheat Sugary-type isoamylase is compared with other sequences available in the database and the results demonstrate that there are three types of isoamylase sequences in plants: those containing 18 exons (the Sugary-type isoamylase gene), those containing 21 exons, and those containing only 1 exon. It is possible that different combinations of isoamylase genes are expressed in different tissues.

Amino Acid Sequence↗
PubMed1975

Sources of the serum isoamylases and their normal range of variation with age.

The isoamylases in various human tissue homogenates and body fluids were separated by agarose gel electrophoresis. Nothing suggested any significant production of amylase in the liver. Minute amounts of amylase belonging to the pancreatic group of isoamylases might be produced by the glands of the proximal duodenum. The specific group of isoamylases produced in the female genital tract could not be demonstrated in serum or urine. The activity of amylase in serum was derived from two groups of isoenzymes, one group originating from the salivary glands, the other from the pancreatic gland. The contribution of each of these two sources to the total serum amylase was determined from early foetal life to adult age. A very low activity of the salivary isoamylases was regularly found in serum from 14-week-old foetuses. The activity increased steadily with age and reached the normal adult level, about 80 U/l, at the age of 5 years. The pancreatic group of isoamylases in serum developed later; the majority of children below 3 months had no demonstrable pancreatic isoamylase activity. The activity rose slowly to reach adult level, about 80 U/l, at the age of 10 to 15 years. The activity did not vary with sex, and the diurnal variation of the isoamylase was negligible. In children with cystic fibrosis of the pancreas the activity of pancreatic isoamylases in serum was low.

Adolescent↗
PubMed1982

Salivary-type hyperamylasemia in primary lung cancer: observation of a possible precursor of the salivary-type isoamylase.

Although recent studies by column chromatography and electrophoresis showed that elevated amylase activity in the body fluids and tumor extracts in patients with primary lung cancer was mainly in the salivary-type isoamylase, neither mechanism nor mature of elevation of amylase have been clarified yet. This study was undertaken in order to make clear the nature of amylase elevated in the body fluids and tumor extracts of patients with primary lung cancer. In addition, amylase contained in the extracts of normal lungs and diseased lungs of patients who had died of various diseases was also studied. Our results revealed that amylase elevated in the body fluids and tumor extracts in patients with primary lung cancer was the salivary-type isoamylase and, moreover, that small amounts of salivary-type isoamylase in normal lung tissues and large amounts in diseased lung tissues were also contained. These facts suggested that salivary-type isoamylase was physiologically contained in normal lung tissues and large amounts in diseased lung tissues were also contained. These facts suggested that salivary-type isoamylase was physiologically contained in normal lung tissues and might be activated through pathological processes, such as inflammation, circulatory disturbance or tumor formation. Two peculiar isoamylases with cathodic mobility on polyacrylamide gel electrophoresis were found. One of them was so unstable that it was converted to the stable salivary-type isoamylase, suggesting the precursor of human salivary isoamylase.

Adenocarcinoma↗
PubMed1999

The starch-debranching enzymes isoamylase and pullulanase are both involved in amylopectin biosynthesis in rice endosperm

The activities of the two types of starch debranching enzymes, isoamylase and pullulanase, were greatly reduced in endosperms of allelic sugary-1 mutants of rice (Oryza sativa), with the decrease more pronounced for isoamylase than for pullulanase. However, the decrease in isoamylase activity was not related to the magnitude of the sugary phenotype (the proportion of the phytoglycogen region of the endosperm), as observed with pullulanase. In the moderately mutated line EM-5, the pullulanase activity was markedly lower in the phytoglycogen region than in the starch region, and isoamylase activity was extremely low or completely lost in the whole endosperm tissue. These results suggest that both debranching enzymes are involved in amylopectin biosynthesis in rice endosperm. We presume that isoamylase plays a predominant role in amylopectin synthesis, but pullulanase is also essential or can compensate for the role of isoamylase in the construction of the amylopectin multiple-cluster structure. It is highly possible that isoamylase was modified in some sugary-1 mutants such as EM-273 and EM-5, since it was present in significant and trace amounts, respectively, in these mutants but was apparently inactive. The results show that the Sugary-1 gene encodes the isoamylase gene of the rice genome.

Journal Article↗