Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
|
| pubmed:dateCreated |
1998-2-23
|
| pubmed:databankReference | |
| pubmed:abstractText |
It has been hypothesized that human mucosal glucoamylase (EC 3.2.1. 20 and 3.2.1.3) activity serves as an alternate pathway for starch digestion when luminal alpha-amylase activity is reduced because of immaturity or malnutrition and that maltase-glucoamylase plays a unique role in the digestion of malted dietary oligosaccharides used in food manufacturing. As a first step toward the testing of this hypothesis, we have cloned human small intestinal maltase-glucoamylase cDNA to permit study of the individual catalytic and binding sites for maltose and starch enzyme hydrolase activities in subsequent expression experiments. Human maltase-glucoamylase was purified by immunoisolation and partially sequenced. Maltase-glucoamylase cDNA was amplified from human intestinal RNA using degenerate and gene-specific primers with the reverse transcription-polymerase chain reaction. The 6,513-base pair cDNA contains an open reading frame that encodes a 1,857-amino acid protein (molecular mass 209,702 Da). Maltase-glucoamylase has two catalytic sites identical to those of sucrase-isomaltase, but the proteins are only 59% homologous. Both are members of glycosyl hydrolase family 31, which has a variety of substrate specificities. Our findings suggest that divergences in the carbohydrate binding sequences must determine the substrate specificities for the four different enzyme activities that share a conserved catalytic site.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
30
|
| pubmed:volume |
273
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
3076-81
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:9446624-Amino Acid Sequence,
pubmed-meshheading:9446624-Animals,
pubmed-meshheading:9446624-Binding Sites,
pubmed-meshheading:9446624-Cattle,
pubmed-meshheading:9446624-Cloning, Molecular,
pubmed-meshheading:9446624-Consensus Sequence,
pubmed-meshheading:9446624-DNA, Complementary,
pubmed-meshheading:9446624-Escherichia coli,
pubmed-meshheading:9446624-Haplorhini,
pubmed-meshheading:9446624-Humans,
pubmed-meshheading:9446624-Intestine, Small,
pubmed-meshheading:9446624-Mice,
pubmed-meshheading:9446624-Molecular Sequence Data,
pubmed-meshheading:9446624-Rabbits,
pubmed-meshheading:9446624-Rats,
pubmed-meshheading:9446624-Recombinant Proteins,
pubmed-meshheading:9446624-Species Specificity,
pubmed-meshheading:9446624-Substrate Specificity,
pubmed-meshheading:9446624-Tissue Distribution,
pubmed-meshheading:9446624-alpha-Glucosidases
|
| pubmed:year |
1998
|
| pubmed:articleTitle |
Human small intestinal maltase-glucoamylase cDNA cloning. Homology to sucrase-isomaltase.
|
| pubmed:affiliation |
United States Department of Agriculture Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030-2600, USA.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
|