Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human small intestinal brush border proteins were studied qualitatively by crossed immunoelectrophoresis. Brush border membranes were purified from human jejunum and the proteins released by Triton X-100. Rabbits were immunized with the released proteins and by using a double layer immunofluorescence technique the obtained antisera were shown to be specific against the brush border proteins. The precipitates obtained in crossed immunoelectrophoresis were identified by enzymatic staining techniques. Sucrase (EC 3.2.1.48), isomaltase EC 3.2.1.10), maltase (EC 3.2.1.20), phloretin-glucosidase (EC 3.2.1.62), lactase (EC3.2.1.23), microvillus aminopeptidase (aminopeptidase (microsomal), EC 3.4.11.2), dipeptidyl peptidase IV (EC 3.4.14.X), and alkaline phosphatase (EC 3.1.3.1) were identified while asparate aminopeptidase (EC 3.4.11.7), gamma-glutamyl transferase (EC 2.3.2.2) and trehalase (EC 3.2.1.28) could not be visualized. This work demonstrates that cross immunoelectrophoresis can be used in the study of human small intestinal brush border proteins.
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PMID:Immunoelectrophoretic studies on human small intestinal brush border proteins. A qualitative study of the protein composition. 36 59

The effect of a new complex oligosaccharide (Bay g 5421) of microbial origin on human intestinal alpha-glucosidehydrolase activity was tested in mucosal homogenate from human small bowel biopsy specimens. The alpha-glucosidehydrolase inhibitor (alpha-GHI) exerted a potent inhibitory effect on glucoamylase, sucrase, and maltase, was minimally effective on isomaltase, and did not affect trehalase and lactase activity. Kinetic analysis revealed a fully competitive type of inhibition with a Ki of 1.3 x 10(-6) M; thus the inhibitor had a 15,000-fold higher affinity to the enzyme sucrase than its natural substrate sucrose. The new compound may prove to be useful in the study of carbohydrate maldigestion and malabsorption and may possibly be of therapeutic benefit in diabetes and obesity.
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PMID:Inhibition of human intestinal alpha-glucosidehydrolases by a new complex oligosaccharide. 44 22

Jejunal mucosal function and structure was examined in 31 patients with ulcerative colitis and 29 patients with Crohn's disease with ileal, ileocolonic or colonic involvement; A significant reduction of the specific activity of disaccharidases (lactase, sucrase and trehalase) in jejunal mucosal homogenate occurred in patients with inflammatory bowel disease. Similarly, alkaline phosphatase was reduced in ulcerative colitis. Several dipeptidases such as glycyl-leucine, leucyl-glycine, glycyl-glycine and valyl-proline hydrolase activities were lower in patients with inflammatory bowel disease than in controls. Histological changes in jejunal mucosal biopsies occurred in 71% of patients with ulcerative colitis and 61% with Crohn's disease. These changes ranged from mild abnormalities of villus architecture to marked reduction of villus height. Most patients with a reduction in mucosal enzymes had concommitant morphological changes in jejunal mucosal biopsy. The results of this study indicate that functional and structural abnormalities of the jejunal mucosa frequently occur in patients with inflammatory bowel disease without radiologic evidence of proximal small bowel involvement.
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PMID:Abnormalities of jejunal mucosal enzymes in ulcerative colitis and Crohn's disease. 47 7

The authors review the contemporary uses of histochemistry for the diagnosis of enzymopathies. Enterokinase, lactase, sucrase and trehalase deficiency can be diagnosed by histochemical methods. In glycogenoses, glycogen storage and glucose-6-phosphatase, acid alpha-glucosidase and phosphorylase deficiencies can be demonstrated. In mucopolysaccharidoses, the accumulation of acid muco-substances and changes in lysosomal enzyme activities can be demonstrated.
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PMID:Possibilities for the cytochemical diagnosis of enzymopathies. 61 85

A close relationship exists between relative disaccharidase activities (maltase, sucrase, trehalase, palatinase, turanase, lactase, and cellobiase) in amniotic fluid and corresponding jejunal mucosa of five human fetuses (16 to 21 weeks of gestation) suggesting that these intestinal enzymes pass into amniotic fluid. Serial determination of disaccharidase activities in amniotic fluid samples collected between 10 and 42 weeks of gestation showed maximum mean activities at 14 to 17 weeks of gestation and a rapid drop to less than 12 per cent maximum values at about 22 weeks. This drop is probably caused by combined effects of decreased extrusion rate of intestinal disaccharidases and increased reabsorption of the enzymes in swallowed amniotic fluid with fetal development.
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PMID:Developmental patterns of intestinal disaccharidases in human amniotic fluid. 64 87

Brush-border membranes were isolated from the rat small intestine and then treated with sodium dodecyl sulphate under non-reducing conditions at room temperature. Analysis of the solubilized components by polyacrylamide-gel electrophoresis identified three major glycoproteins that co-migrate with glucoamylase-maltase-sucrase, lactase and isomaltase-maltase-sucrase activities. High activities of alkaline phosphatase and trehalase were detectable, but they could not be attributed to distinct co-migrating protein bands. Analysis of mucosa from the distal small intestine by the same methods showed a pattern of bands different from that obtained with the proximal intestine, which appeared to correlate with the relative deficiency of some of the enzymes in the distal region.
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PMID:The identification of rat intestinal membrane enzymes after electrophoresis on polyacrylamide gels containing sodium dodecyl sulphate. 69 63

The gastric region of 5-week-old female Wistar rats was irradiated daily with 500 rad of X-ray up to a total of six times. Goblet cells and marker enzymes of the small intestine, such as lactase, trehalase, and maltase, appeared in the pyloric region of the glandular stomach of the rats from the 1st week after final irradiation. Intestinal type crypt without Paneth cells was observed from the 8th week. Sucrase activity appeared from the 26th week. Intestinal metaplasia with Paneth cells appeared from the 71st week. The number of goblet cells, intestinal type crypts, and Paneth cells increased with age. Gastric adenocarcinoma did not develop after irradiation.
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PMID:Experimentally induced intestinal metaplasia in Wistar rats by X-ray irradiation. 70 Mar 22

The separation by polyacrylamide gel electrophoresis and subsequent enzymatic analysis of the components of the guinea pig intestinal brush border membrane revealed the presence of three enzyme complexes: maltase-glucoamylase, maltase-sucrase-glucoamylase and maltase-sucrase. Additional bands possessing lactase, trehalase and alkaline phosphatase activity were identified but no phlorizin hydrolase or palatinase was detectable. After exposure to strong dissociating conditions the bands possessing enzymatic activity were either absent or greatly reduced in intensity.
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PMID:Glycosidases of the guinea pig brush border membrane. 86 Dec 25

Small intestinal morphologic and biochemical changes were studied following jejuno-ileal bypass for obesity after body weight stabilization had occurred. Four patients underwent biopsy of in-continuity and bypassed jejunal and ileal segments of the small intestine 11 to 22 months after the bypass operation. Microscopically, marked mucosal villus hypertrophy of the in-continuity bowel was observed, especially in the ileum. Bypassed jejunal mucosa underwent atrophy compared with pre-bypass jejunum, whereas bypassed ileum appeared similar microscopically to pre-bypass ileum. The specific activities of mucosal disaccharidase enzymes (maltase, sucrase, lactase and trehalase) in units per mg protein remained similar to pre-bypass levels in segments of the in-continuity jejunum and the bypassed jejunum and ileum. On the other hand, elevated mucosal disaccharidase levels were measured in biopsy specimens of the in-continuity ileum. Total enzyme activity per unit length of intestine, however, was estimated to be elevated in both in-continuity jejunum and ileum secondary to mucosal villus hypertrophy. These data indicate that following small bowel bypass: (1) the in-continuity ileum undergoes greater biochemical and morphologic adaptation than the jejunum; and (2) intraluminal nutrients and chyme appear to be essential to maximal intestinal adaptation.
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PMID:Gastrointestinal adaptation following small bowel bypass for obesity. 87 Dec 20

On the basis of comparative determinations of the activities of dipeptidases and disaccharidases of the mucous membrane of the small intestine (proximal jejunum) clear correspondences between the morphological findings and the biochemical parameters were the result. L-alanyl-L-prolin-dipeptidase and glycyl-L-valin-dipeptidase as well as lactase, saccharase, maltase and trehalase were determined in altogether 45 children with various malabsorption syndromes of different age in different stages of disease. Diminutions of the activity of the dipeptidases were to be proved analogously to maltase, saccharase and lactase, too, in most cases of subtotal or total villous atrophy. From the results conclusions may be derived to the restricted ability of protein absorption in chronic disease of the small intestine.
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PMID:[L-alanyl-L-proline-dipeptidase and glycyl-L-valine-depeptidase in malabsorption syndrome]. 96 Sep 1


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