FUNGAL GLUCOAMYLASE SUPPLEMENTS ON STARCH DIGESTION IN GLUCOSIDASE DEFICIENT

真菌葡糖淀粉酶补充葡萄糖苷酶缺乏症中的淀粉消化

• 批准号: 8356720
• 负责人: Mark Alan Gilger
• 金额: $ 0.44万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8356720
• 关键词: Alpha-glucosidase; Amylases; Amylopectin; Assimilations; Binding; Biological Assay; Biopsy; Brush Border; Carbohydrates; Child; Clinical; Clinical Research; Colon; Complex; Dextrins; Diarrhea; Digestion; Disaccharidases; Energy Intake; Enzymes; Failure; Failure to Thrive; Family; Food; Funding; Gases; Generic Drugs; Genes; Genomics; Glucan 1,4-alpha-Glucosidase; Glucose; Glycogen; Grant; Human; Immunoprecipitation; Individual; Inherited; Intestines; Lactase; Length; Maltose; Membrane; Monosaccharides; Mucous Membrane; National Center for Research Resources; Oligo-1,6-Glucosidase; Oligosaccharides; Oral; Pancreas; Paper; Pattern; Peptides; Principal Investigator; Proteins; Proteomics; Protocols documentation; Reporting; Research; Research Infrastructure; Resources; Role; Salivary; Sampling; Secondary to; Siblings; Small Intestines; Source; Starch; Subgroup; Substrate Specificity; Sucrase; Symptoms; Syndrome; United States National Institutes of Health; Writing; absorption; aged; alpha-amylase; clinical Diagnosis; congenital sucrose isomaltose malabsorption; cost; dextrin; dietary restriction; enzyme therapy; glucose production; glucosidase; jejunum; sucrase-isomaltase-maltase; sugar

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ABSTRACT Starches and sugars make up 60-90% of human dietary energy intakes. All food carbohydrates (CHO)s are digested in the small intestine to monosaccharides before absorption by a family of membrane bound luminal enzymes called disaccharidases. The best studied disaccharidases are lactase, and sucrase-isomaltase. Because of recognizable clinical symptoms, congenital sucrase-isomaltase deficiencies (CSID) have been studied at clinical, proteomic and genomic levels. While the role of salivary and pancreatic alpha-amylase activities in starch digestion are well known, the roles of mucosal alpha-glucosidases activities are less understood. Alpha-amylases release only 4% of the glucose present in amylopectin. The remaining 96% of products are soluble glucose oligomers with a conserved pattern of lengths. These oligomers, including maltose (G2) and lengths through G40 require further digestion. Mucosal glucosidases release free glucose from the non-reducing ends of the soluble oligomers. Differentiation of amylase from glucosidases activity was first reported in 1880 after discovery of maltase activity in small intestine and its absence in the pancreas. In the 1960s Dahlqvist found that 4 different maltase activities could be identified in the human jejunum; two were isolated with sucrase-isomaltase (SI) activities and two, that were free of all other disaccharidase activities, were called maltase-glucoamylase (MGAM). In the 1980s Hermann, et al. proved that mucosal maltase activities are a subgroup of the glucosidases and that while substrate specificities of SI and MGAM are identical, the activity of MGAM was 100 fold greater and the concentration of SI peptide is 20 fold greater. This dictates that both must be investigated to understand mucosal glucose production from food starches. This protocol is a generic version of H-20932 which was written for a family with hereditary poor starch digestion. In this protocol we will study a national sample of children with similar low duodenal biopsy maltase and normal sucrase activities. The impetus for this study relates to two young siblings with failure-to-thrive that is believed to be secondary to starch intolerance. They have sought treatment for this condition that is currently managed by dietary restrictions (see H-20932). In the older child the condition has been attributed to biopsy-proven, congenital absence of the intestinal brush border enzyme called maltase. The glucosidase activities for the biopsy were, sucrase 40.6 (nl 25), maltase 87.1 (nl 100), and palatinase 6.8 (nl 5). All values were uM/min/g protein. Glucosidase enzymes reduce oligosaccharides to simple glucose that can be absorbed into the body. Failure results in undigested complex carbohydrates that pass to the colon and provoke gas, bloating, irritability and diarrhea. A similar syndrome was described by Lebenthal in 1994, nine children aged from 6-107 months were found to have clinical starch intolerance. Lebenthal used glycogen as substrate for a mucosal biopsy glucosidase assay and reported that deficient activity generally agreed with his clinical diagnosis. We now know that glycogen substrate is only about 80% specific for the MGAM activity of the mucosa. In the 14 years since Lebenthals paper we have shown that four glucosidases participate in the post-amylase digestion of oligosaccharides to glucose and that specific substrates cannot dissect these glucosidase activities. We have found that immunoprecipitation of the activities can resolve individual contributions by the different genes to starch digestion. HYPOTHESIS Supplemental oral enzyme therapy, containing fungal amyloglucosidase, will be beneficial to symptomatic children with congenital maltase glucoamylase deficiency as shown by symptom improvement and increased breath sample enrichment values (objective surrogate of brush border alpha-limit-dextrin digestion and product assimilation) . I. SPECIFIC AIMS 1. To demonstrate that supplemental oral enzyme therapy, containing fungal amyloglucosidase, is beneficial to symptomatic children with congenital maltase glucoamylase deficiency. 2. To demonstrate symptom improvement 3. To demonstrate increased breath sample enrichment values (objective surrogate of brush border alpha-limit-dextrin digestion and product assimilation)

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 抽象淀粉和糖占人类饮食能量摄入量的60-90％。所有食物碳水化合物（CHO）s在小肠到单糖中被消化，然后由称为二糖酶的膜结合的腔腔酶吸收。最佳研究的二糖尿酶是乳糖酶和苏糖酶 - 异构酶。由于可识别的临床症状，已经在临床，蛋白质组学和基因组水平上研究了先天性舒适酶 - 异构酶缺陷（CSID）。虽然唾液和胰腺淀粉酶在淀粉消化中的作用是众所周知的，但粘膜α-葡萄糖苷酶活性的作用却较少。 α-淀粉酶仅释放淀粉蛋白中存在的葡萄糖的4％。其余96％的产品是具有保守长度模式的可溶性葡萄糖低聚物。这些低聚物，包括麦芽糖（G2）和通过G40的长度需要进一步的消化。粘膜葡萄糖酶从可溶性低聚物的非还原末端释放游离葡萄糖。淀粉酶与葡萄糖酶活性的分化在1880年在小肠中发现了麦芽糖酶活性后，首次报道了糖苷酶活性。在1960年代，达尔克维斯特（Dahlqvist）发现，可以在人类的空肠中确定4种不同的麦芽糖酶活动。用舒适酶 - 异构酶（SI）活性分离出两种，而没有所有其他二糖酶活性，称为麦芽糖酶 - 葡萄糖氨基酶（MGAM）。在1980年代，赫尔曼等人。事实证明，粘膜麦芽糖酶活性是葡萄糖酶的亚组，尽管Si和MGAM的底物特异性相同，但MGAM的活性大100倍，SI肽的浓度较高20倍。这决定两者都必须进行研究，以了解食物淀粉的粘膜葡萄糖产生。 该协议是H-20932的通用版本，该版本是为遗传性较差淀粉消化的家庭编写的。在此方案中，我们将研究具有类似低十二指肠活检麦芽糖酶和正常Sucrase活动的儿童的全国样本。这项研究的动力涉及两个年轻的兄弟姐妹，但据信是淀粉不耐受的次数。他们寻求治疗目前受饮食限制管理的治疗（请参阅H-20932）。在年龄较大的孩子中，病情归因于证实活检，先天性缺乏称为麦芽糖酶的肠道边界酶。活检的葡萄糖酶活性是Sucrase 40.6（NL 25），麦芽糖酶87.1（NL 100）和palatinase 6.8（NL 5）。所有值均为UM/min/g蛋白。 葡萄糖酶酶将寡糖降低到可以吸收到体内的简单葡萄糖。故障导致未消除的复杂碳水化合物传递到结肠并促进气体，腹胀，易怒和腹泻。 Lebenthal在1994年描述了类似的综合征，发现从6-107个月大的9名儿童患有临床淀粉不耐受。 Lebenthal使用糖原作为粘膜活检葡萄糖酶测定的底物，并报告说，缺乏活性通常与他的临床诊断一致。我们现在知道，对于粘膜的MGAM活性，糖原底物的特异性仅约80％。自从Lebenthals论文以来的14年中，我们已经表明，四种葡萄糖酶参与了寡糖的 - 淀粉酶消化对葡萄糖的消化，并且特定的底物不能剖析这些葡萄糖酶活性。我们发现，对活动的免疫沉淀可以解决不同基因对淀粉消化的个人贡献。 假设补充口服酶疗法含有真菌淀粉糖酶酶，将有利于有症状的先天性麦芽糖糖酶葡萄糖酶缺乏症的症状儿童，如症状改善和呼吸样品富集值的增加所示（刷子的替代brush bortha-bortha-bortha-bortha-bortha-limit-limit-dextrin-脱氧蛋白 - 脱氧蛋白 - 脱氧蛋白 - 脱氧蛋白含量和产物）。 I.具体目标 1。证明含有真菌链淀粉酶酶的补充口服酶治疗对有症状的先天性麦芽糖酶葡萄糖酶缺乏症有益。 2。证明症状改善 3。证明呼吸样品富集值增加（刷子边框α-丝丝 - 脱酮消化和产品同化的客观替代）