PMID- 12535607
OWN - NLM
STAT- MEDLINE
DCOM- 20030310
LR  - 20190610
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 1645
IP  - 1
DP  - 2003 Jan 31
TI  - Multiple sugar binding sites in alpha-glucosidase.
PG  - 22-9
AB  - Twenty-five analogs of D-glucose were examined as reversible inhibitors of yeast 
      alpha-glucosidase (EC 3.2.1.20). The K(i) values range from 0.38 mM for 
      6-deoxy-D-glucose (quinovose) to 1.0 M for D-lyxose at pH=6.3 (0.1 M NaCl, 25 
      degrees ). All the monosaccharides and the three disaccharides (maltose, 
      isomaltose and alpha,alpha-trehalose) were found to be linear competitive 
      inhibitors with respect to alpha-p-nitrophenyl glucoside (pNPG) hydrolysis. 
      Multiple inhibition analysis reveals that there are at least three monosaccharide 
      binding sites on the enzyme. One of these can be occupied by glucose 
      [K(i)=1.8(+/-0.1) mM], one by D-galactose [K(i)=164(+/-11) mM] and one by 
      D-mannose [K(i)=120(+/-9) mM]. The pH dependence for glucose binding closely 
      follows that of V/K [pK(a1)=5.55(+/-0.15), pK(a2)=6.79(+/-0.15)], but the binding 
      of mannose does not. Although the glucose subsite can be occupied simultaneously 
      with the mannose or galactose subsites in the enzyme-product complex, no 
      transglucosylation can be detected between pNPG and either mannose or galactose. 
      This suggests that neither of these nonglucose subsites can be occupied in a 
      productive manner in the covalent glucosyl-enzyme intermediate.
FAU - Yao, Xiaojie
AU  - Yao X
AD  - Department of Chemistry, Tulane University, 6400 Freret St., New Orleans, LA 
      70118-5698, USA.
FAU - Mauldin, Rebecca
AU  - Mauldin R
FAU - Byers, Larry
AU  - Byers L
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - 0 (Glucosides)
RN  - 0 (Glycoside Hydrolase Inhibitors)
RN  - 2492-87-7 (4-nitrophenyl beta-D-glucoside)
RN  - EC 3.2.1.20 (alpha-Glucosidases)
RN  - IY9XDZ35W2 (Glucose)
RN  - PHA4727WTP (Mannose)
RN  - X2RN3Q8DNE (Galactose)
SB  - IM
MH  - Binding Sites
MH  - Binding, Competitive
MH  - Galactose/pharmacology
MH  - Glucose/*analogs & derivatives/pharmacology
MH  - Glucosides/*metabolism
MH  - *Glycoside Hydrolase Inhibitors
MH  - Hydrogen-Ion Concentration
MH  - Kinetics
MH  - Mannose/pharmacology
MH  - Models, Molecular
MH  - Saccharomyces cerevisiae
MH  - alpha-Glucosidases/chemistry/metabolism
EDAT- 2003/01/22 04:00
MHDA- 2003/03/11 04:00
CRDT- 2003/01/22 04:00
PHST- 2003/01/22 04:00 [pubmed]
PHST- 2003/03/11 04:00 [medline]
PHST- 2003/01/22 04:00 [entrez]
AID - S1570963902004740 [pii]
AID - 10.1016/s1570-9639(02)00474-0 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 2003 Jan 31;1645(1):22-9. doi: 
      10.1016/s1570-9639(02)00474-0.