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PDBsum entry 3l2m
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References listed in PDB file
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Key reference
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Title
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X-Ray crystallographic analyses of pig pancreatic alpha-Amylase with limit dextrin, Oligosaccharide, And alpha-Cyclodextrin.
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Authors
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S.B.Larson,
J.S.Day,
A.Mcpherson.
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Ref.
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Biochemistry, 2010,
49,
3101-3115.
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PubMed id
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Abstract
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Further refinement of the model using maximum likelihood procedures and
reevaluation of the native electron density map has shown that crystals of pig
pancreatic alpha-amylase, whose structure we reported more than 15 years ago, in
fact contain a substantial amount of carbohydrate. The carbohydrate fragments
are the products of glycogen digestion carried out as an essential step of the
protein's purification procedure. In particular, the substrate-binding cleft
contains a limit dextrin of six glucose residues, one of which contains both
alpha-(1,4) and alpha-(1,6) linkages to contiguous residues. The disaccharide in
the original model, shared between two amylase molecules in the crystal lattice,
but also occupying a portion of the substrate-binding cleft, is now seen to be a
tetrasaccharide. There are, in addition, several other probable monosaccharide
binding sites. Furthermore, we have further reviewed our X-ray diffraction
analysis of alpha-amylase complexed with alpha-cyclodextrin. alpha-Amylase binds
three cyclodextrin molecules. Glucose residues of two of the rings superimpose
upon the limit dextrin and the tetrasaccharide. The limit dextrin superimposes
in large part upon linear oligosaccharide inhibitors visualized by other
investigators. By comprehensive integration of these complexes we have
constructed a model for the binding of polysaccharides having the helical
character known to be present in natural substrates such as starch and glycogen.
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Secondary reference #1
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Title
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Refined molecular structure of pig pancreatic alpha-Amylase at 2.1 a resolution.
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Authors
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S.B.Larson,
A.Greenwood,
D.Cascio,
J.Day,
A.Mcpherson.
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Ref.
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J Mol Biol, 1994,
235,
1560-1584.
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PubMed id
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Secondary reference #2
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Title
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X-Ray crystallographic analysis of swine pancreas alpha-Amylase
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Authors
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A.Mcpherson,
A.Rich.
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Ref.
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biochim biophys acta, 1972,
285,
493.
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