Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to measure the effect of free glutamine or glutamic acid supplementation on small intestinal growth and disaccharidase enzyme activity in 7-day-old miniature piglets. The piglets received one of three total parenteral nutrition solutions exclusively for 7 days. All three solutions were isonitrogenous and isocaloric, and glutamine or glutamic acid was included at physiological levels (5% of the total amino acid content) in two of the three solutions; the third (control) contained neither glutamine nor glutamic acid. No differences were seen between groups in plasma glutamine or glutamic acid concentrations. Similarly, no effect was observed on small intestinal protein or DNA content or on the specific activities of lactase, sucrase, or maltase. These data demonstrate that in the healthy miniature piglet, parenteral glutamine or glutamic acid supplemented at physiological doses does not influence small intestinal growth and development.
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PMID:Glutamine or glutamic acid effects on intestinal growth and disaccharidase activity in infant piglets receiving total parenteral nutrition. 167 20

Six litters of newborn crossbred piglets were utilized to examine 1) the effects of substituting 20% of the protein of an all-milk protein liquid diet with a soy protein isolate (milk-soy diet) on small intestinal variables and 2) the effects of supplementing this milk-soy diet with 25 g of either putrescine or ethylamine per kilogram diet on small intestinal variables. Small intestinal xylose absorption tended to increase from wk 1 to wk 2 of age in pigs fed the milk, putrescine and ethylamine diets, but not in pigs fed the milk, putrescine and ethylamine diets, but not in pigs fed the unsupplemented milk-soy diet. Crypt depth in pigs fed the milk-soy diet tended to be less (9.4%; P greater than .10) than the crypt depth in pigs fed the other diets, but mitotic index was not different (P greater than .10) among diets. Mucosal protein, DNA and RNA concentrations and mucosal brush border sucrase and cytosolic dipeptidase activities tended to be least in pigs fed the putrescine and ethylamine diets. Concentration of mucosal putrescine was greatest (P less than .002) in the distal regions of the small intestine of pigs fed putrescine. Mucosal ornithine decarboxylase activity was inhibited by putrescine (P less than .02), but it was not affected by the soybean protein isolate used in this study. Supplementing soy protein isolate diets with amines may enhance intestinal absorption and enterocyte proliferation.
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PMID:Effects of dietary amines on small intestinal variables in neonatal pigs fed soy protein isolate. 169 Jan 99

Factors, such as insulin, found in human and pig colostrum and mature milk likely influence small intestinal growth and development. Although pharmacologic doses of insulin injected parenterally may accelerate small intestinal development in altricial animals such as the rodent, the effects of oral insulin on intestinal development have not been studied. In the first of two studies, we randomized 2-d-old miniature piglets to receive bottle-feedings of a swine weaning milk formula with (group F + I) or without (group F) the addition of insulin. Serum glucose, insulin, and cortisol were measured before and 1 h after the first feeding the piglets received at our facility. In the second study, piglets were randomized (groups F and F + I) and fed for 6 d, after which blood samples were obtained as in the first experiment. The piglets were then killed and the small intestine removed for analysis. We found no differences between groups in serum glucose, insulin, and cortisol at both 2 and 8 d of age, both before and after feeding. In the second experiment, small intestinal weight was greater in the F + I than in the F group. Although no differences were noted between groups in the jejunum, values were greater for group F + I versus group F for ileal mucosal weight, protein, RNA, lactase, and maltase activities. No differences were found between groups in ileal DNA or sucrase activity. We conclude that the administration of oral insulin stimulated an increase in ileal mass and disaccharidase activity in the newborn miniature pig without apparent concomitant changes in serum glucose, insulin, or cortisol.
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PMID:Oral insulin increases small intestinal mass and disaccharidase activity in the newborn miniature pig. 169 70

The gene encoding glucosyltransferase responsible for water-insoluble glucan synthesis (GTF-I) of Streptococcus sobrinus (formerly Streptococcus mutans 6715) was cloned, expressed, and sequenced. A gene bank from S. sobrinus 6715 DNA was constructed in vector pUC18 and screened with anti-GTF-I antibody to detect clones producing GTF-I peptide. Five immunopositive clones were isolated, all of which produced peptides that bound alpha-1,6 glucan. GTF-I activity was found in only two large peptides: one stretching over the full length of the GTF-I peptide and composed of about 1,600 amino acid residues (AB1 clone) and the other lacking about 80 N-terminal residues and about 260 C-terminal residues (AB2 clone). A deletion study of the AB2 clone indicated that specific glucan binding, which is essential for water-insoluble glucan synthesis, was lost prior to sucrase activity with an increase in deletion from the 3' end of the GTF-I gene. These results suggest that the GTF-I peptide consists of three segments: that for sucrose splitting (approximately 1,100 residues), that for glucan binding (approximately 240 residues), and that of unknown function (approximately 260 residues), in order from the N terminus. The primary structure of the GTF-I peptide, deduced by DNA sequencing of the AB1 clone, was found to be very similar to that of the homologous protein from another strain of S. sobrinus.
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PMID:Peptide sequences for sucrose splitting and glucan binding within Streptococcus sobrinus glucosyltransferase (water-insoluble glucan synthetase). 170 6

A sucrose-inducible alpha-glucosidase activity that hydrolyzes sucrose in Candida albicans has been demonstrated previously. The enzyme is assayable in whole cells and was inhibited by both sucrose and maltose. A C. albicans gene (CASUC1) that affects sucrose utilization and alpha-glucosidase activity was cloned by expression in a Saccharomyces cerevisiae suc2 mutant (2102) devoid of invertase genes. CASUC1 enabled the S. cerevisiae mutant to utilize both sucrose and maltose. DNA sequence analysis revealed that CASUC1 encodes a putative zinc finger-containing protein with 28% identity to a maltose-regulatory gene (MAL63) of S. cerevisiae. The gene products of CASUC1 and MAL63 are approximately the same size (501 and 470 amino acids, respectively), and each contains a single zinc finger located at the N terminus. The zinc fingers of CASUC1 and MAL63 comprise six conserved cysteines (C6 zinc finger) and are of the general form Cys-Xaa2-Cys-Xaa6-Cys-Xaavariable-Cys-Xaa2-Cys-+ ++Xaa6-Cys (where Xaan indicates a stretch of the indicated number of any amino acids). Both contain five amino acids in the variable region. CASUC1 also complemented the maltose utilization defect of an S. cerevisiae mutant (TCY-137) containing a defined mutation in a maltose-regulatory gene. The sucrose utilization defect of type II Candida stellatoidea, a sucrase-negative mutant of C. albicans, was corrected by CASUC1. Determinations of alpha-glucosidase activity in whole cells revealed that activity was restored in transformants cultivated on either sucrose or maltose. To our knowledge, this is the first zinc finger-encoding gene, as well as the first putative regulatory gene, to be identified in C. albicans.
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PMID:A zinc finger protein from Candida albicans is involved in sucrose utilization. 172 10

To investigate the role and mechanism of action of epidermal growth factor (EGF) in the intestinal epithelium, we have studied its influence on proliferation and differentiation of Caco-2 cells, a human colon adenocarcinoma cell line exhibiting several characteristics of adult small intestinal enterocytes. A clone of Caco-2 cells synthesizing minimal amounts of transforming growth factor-alpha (TGF-alpha)/epidermal growth factor (EGF)-like activity was used in these studies. Cells grown in the presence of 20-200 ng EGF/ml exhibited increased DNA synthesis and proliferation; formation of morphologically poorly differentiated multilayers was observed at 200 ng EGF/ml. At all concentrations tested EGF produced a significant and marked reduction in sucrase activity, whereas other brush-border enzymes (aminopeptidase N, alkaline phosphatase, dipeptidylpeptidase IV) were only marginally affected. EGF influenced sucrase expression at two different levels. At 20 ng/ml, it affected primarily sucrase-isomaltase processing in the endoplasmic reticulum and/or increased its degradation. At 200 ng EGF/ml, a significant and marked reduction in sucrase-isomaltase mRNA levels and biosynthesis was observed. These results demonstrated that EGF has important and selective effects on Caco-2 cell proliferation and differentiation and may affect different cellular activities depending on its concentration.
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PMID:Inhibition of sucrose-isomaltase expression by EGF in the human colon adenocarcinoma cells Caco-2. 176 18

The ERG9 gene of Saccharomyces cerevisiae has been cloned by complementation of the erg9-1 mutation which affects squalene synthetase. From the 5 kb insert isolated, the functional gene has been localized on a DNA fragment of 2.5 kb. The presence of squalene synthetase activity in E. coli bearing the yeast DNA fragment isolated, indicates that the structural gene encoding squalene synthetase has been cloned. The sequence of the 2.5 kb fragment contains an open reading frame which could encode a protein of 444 amino acids with a deduced relative molecular mass of 51,600. The amino acid sequence reveals one to four potential transmembrane domains with a hydrophobic segment in the C-terminal region. The N-terminus of the deduced protein strongly resembles the signal sequence of yeast invertase suggesting a specific mechanism of integration into the membranes of the endoplasmic reticulum.
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PMID:Isolation and primary structure of the ERG9 gene of Saccharomyces cerevisiae encoding squalene synthetase. 180 26

A series of deletions were made at upstream region of SUC2 gene with the direction from about -900 bp to the initiation codon. The DNA fragments, which contain SUC22 gene and its deleted upstream region, were inserted into multicopy plasmid. After transforming resulted plasmid into SUC strain, the invertase activities produced by the transformants were determined. Under glucose repressing condition, the glycosylated invertase produced by transformants with deletion from -636 bp to -179 bp of SUC2 gene were gradually increased. The transformants with deletion down to -223 bp and -179 bp could produce about 100 times higher glycosylated invertase activity as compared to wild type. Under glucose derepressing condition, the glycosylated invertase produced by transformants with deletion from -395 bp to -179 bp of SUC2 gene were only slightly more than that produced under glucose repressing condition. Under either glucose repressing or derepressing condition, the transformants with deletion at -89 bp and -41 bp produced only a little of glycosylated invertase, while they produced remarkably higher nonglycosylated invertase activity.
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PMID:[The effects of upstream region of SUC2 gene on its expression]. 188 28

The absence of intraluminal nutrients during weaning in rats was shown to result in altered intestinal growth and maturation. In this study intestinal length, mucosal weight, DNA, protein, and total disaccharidase activities were significantly lower in animals sustained by intravenous nutrients over the normal weaning age than were normally weaned controls but were greater than preweaning values. Absorptive capacity for sucrose (assessed by hydrogen-gas production) was diminished, directly linking incomplete maturation of sucrase to diminished intestinal function. To determine whether these alterations were permanent, rats previously deprived of intraluminal nutrients over the weaning period were refed. Eight days after refeeding, all variables except total lactase had attained values found in normally weaned age-matched controls, including absorptive capacity for sucrose. Although intestinal growth and maturation is abnormal in the absence of intraluminal nutrients during weaning, the abnormalities are not permanent and are rapidly corrected upon refeeding.
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PMID:Altered maturation of small intestinal function in the absence of intraluminal nutrients: rapid normalization with refeeding. 189 74

Mucosal disaccharidases and ornithine decarboxylase activities were measured in malnourished, preweaning (19 days), post weaning (24 days) and young adult (37 days) rats. Malnutrition resulted in decreased body weight, intestinal weight, DNA and protein content. Mucosal Prot/DNA ratios were elevated in the ileal segments of the 24 and 37 day rats. Preweaned malnourished rats had significantly enhanced lactase specific activity in both jejunal and ileal segments. Adult malnourished rats showed enhanced jejunal lactase and sucrase activities which were not accompanied by elevated ornithine decarboxylase values. Mucosal sucrase and ornithine decarboxylase specific activities were significantly elevated in the ileal segment of the 24 and 37 day old malnourished rats. Studies of adult rats showed that these increased specific activities were located in the mature enterocytes at the villus tip, and persisted during a 24 h diurnal cycle. DFMO administration for 4 days completely inhibited mucosal ornithine decarboxylase and abolished the rise of ileal sucrase activity. We concluded that the intestinal response to reduced food intake is age related and differs in the jejunum and ileum: ornithine decarboxylase and polyamines are involved in ileal adaptation to malnutrition in postweaned and adult rats.
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PMID:Adaptive response of ileal mucosa to malnutrition in the rat: role of polyamines. 192 51


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