Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-5-21
pubmed:abstractText
Cell-free extracts of cellobiose-grown cells of the hyperthermophile Pyrococcus furiosus contain very high activities (19.8 U/mg) of a beta-glucosidase. The cytoplasmic enzyme was purified 22-fold to apparent homogeneity, indicating that the enzyme comprises nearly 5% of the total cell protein. The native beta-glucosidase has a molecular mass of 230 +/- 20 kDa, composed of 58 +/- 2-kDa subunits. The enzyme has a pI of 4.40. Thiol groups are not essential for activity, nor is the enzyme dependent on divalent cations or a high ionic strength. The enzyme shows optimum activity at pH 5.0 and 102-105 degrees C. From Lineweaver-Burk plots, Vmax values of 470 U/mg and 700 U/mg were found for cellobiose (Km = 20 mM) and p-nitrophenyl-beta-D-glucopyranoside (Km = 0.15 mM), respectively. The purified enzyme also exhibits high beta-galactosidase activity and beta-xylosidase activity, but shows no activity towards alpha-linked disaccharides or beta-linked polymers, like cellulose. The purified beta-glucosidase shows a remarkable thermostability with a half life of 85 h at 100 degrees C and 13 h at 110 degrees C.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
213
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
305-12
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Purification and characterization of an extremely thermostable beta-glucosidase from the hyperthermophilic archaeon Pyrococcus furiosus.
pubmed:affiliation
Department of Microbiology, Wageningen Agricultural University, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't