TY - JOUR
T1 - Dissociation of the cellulosome of Clostridium thermocellum under nondenaturing conditions
AU - Morag, Ely
AU - Yaron, Sima
AU - Lamed, Raphael
AU - Kenig, Rina
AU - Shoham, Yuval
AU - Bayer, Edward A.
N1 - Funding Information:
This researchw as supportedb y the Israel Science Foundation administered by the Israel Academy of Sciencesa nd Humanities.T echnical support was provided by the Technion Otto Meyerhof BiotechnologyL aboratoriese stablished by the Minerva Foundation, Germany.
PY - 1996/11/15
Y1 - 1996/11/15
N2 - The cellulosome from the anaerobic, thermophilic, cellulolytic bacterium, Clostridium thermocellum, was dissociated under nondenaturing conditions by incubation at 60°C in the combined presence of EDTA and cellulose. This approach differs from previous strategies in that detergents were not necessary for dissociation of the subunits. Selected enzymatic subunits could be isolated with relative ease. One of these is the major cellulosomal cellobiohydrolase, CelS (previously designated subunit S8 or S(s)). Both the intact cellulosome complex and the combined dissociated subunits exhibited similar levels of activities on soluble and acid-swollen cellulosic substrates. In contrast, the mixture of the free enzymatic subunits was markedly deficient in its degradation of crystalline cellulose compared with that of the intact cellulosome. The results support the critical role of divalent cations, e.g. calcium, in the stability of the cellulosome complex. In addition, the results reinforce previous indications that the cellulosome undergoes conformational changes upon binding to cellulose.
AB - The cellulosome from the anaerobic, thermophilic, cellulolytic bacterium, Clostridium thermocellum, was dissociated under nondenaturing conditions by incubation at 60°C in the combined presence of EDTA and cellulose. This approach differs from previous strategies in that detergents were not necessary for dissociation of the subunits. Selected enzymatic subunits could be isolated with relative ease. One of these is the major cellulosomal cellobiohydrolase, CelS (previously designated subunit S8 or S(s)). Both the intact cellulosome complex and the combined dissociated subunits exhibited similar levels of activities on soluble and acid-swollen cellulosic substrates. In contrast, the mixture of the free enzymatic subunits was markedly deficient in its degradation of crystalline cellulose compared with that of the intact cellulosome. The results support the critical role of divalent cations, e.g. calcium, in the stability of the cellulosome complex. In addition, the results reinforce previous indications that the cellulosome undergoes conformational changes upon binding to cellulose.
KW - Clostridium thermocellum
KW - cellulases
KW - cellulose degradation
KW - cellulosome
KW - multi-enzyme complex
KW - subunit dissociation
UR - http://www.scopus.com/inward/record.url?scp=0030588681&partnerID=8YFLogxK
U2 - 10.1016/S0168-1656(96)01601-X
DO - 10.1016/S0168-1656(96)01601-X
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AN - SCOPUS:0030588681
SN - 0168-1656
VL - 51
SP - 235
EP - 242
JO - Journal of Biotechnology
JF - Journal of Biotechnology
IS - 3
T2 - Proceedings of the 1995 Workshop on Environmental Biotechnology
Y2 - 28 November 1995 through 28 November 1995
ER -