2013 Fiscal Year Final Research Report
Molecular analysis of two novel carbohydrate phosphorylases
| Project/Area Number |
24780091
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Applied biochemistry
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| Research Institution | Hokkaido University |
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Principal Investigator |
SABURI Wataru 北海道大学, (連合)農学研究科(研究院), 助教 (00598089)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | マンノシルグルコースホスホリラーゼ / マンナン / 基質特異性 / Ruminococcus albus / 活性中心 |
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| Research Abstract |
A ruminal anaerobic baceteium, Ruminococcus albus, has two mannosylglucose phosphorylase isozymes (Type-I and Type-II), phosphorolyzing mannosylglucose to alpha-mannose 1-phosphate and glucose. Anyalysis of substrate specificity revealed that Type-I was specific to mannosylglucose, but Type-II had higher activity to mannooligosaccharide than mannosylglucose. These enzymes showed different acceptor substrate specificity in the synthetic reaction: Type-I enzyme showed synthetic activity to 6-OH glucose derivatives unlike in contrast to Type-II, which was completely inert to these substrates. Asp129 of Type-I enzyme was determined to be catalytic amino acid residue based on sequence comparison and site-directed mutagenesis analysis. Ile212 of Type-I enzyme was important for recognition of 6-OH glucose derivatives as acceptor substrates in the synthetic reaction (reverse reaction).
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