KOPS - Das Institutionelle Repositorium der Universität Konstanz

Malonate decarboxylase of Malonomonas rubra, a novel type of biotin-containing acetyl enzyme

Malonate decarboxylase of Malonomonas rubra, a novel type of biotin-containing acetyl enzyme

Zitieren

Dateien zu dieser Ressource

Prüfsumme: MD5:c5ed5395d4f90b62e6af6c9720537b03

HILBI, Hubert, Irmtraut DEHNING, Bernhard SCHINK, Peter DIMROTH, 1992. Malonate decarboxylase of Malonomonas rubra, a novel type of biotin-containing acetyl enzyme. In: European Journal of Biochemistry. 207(1), pp. 117-123

@article{Hilbi1992Malon-6660, title={Malonate decarboxylase of Malonomonas rubra, a novel type of biotin-containing acetyl enzyme}, year={1992}, number={1}, volume={207}, journal={European Journal of Biochemistry}, pages={117--123}, author={Hilbi, Hubert and Dehning, Irmtraut and Schink, Bernhard and Dimroth, Peter} }

2011-03-24T17:28:08Z First publ. in: European Journal of Biochemistry 207 (1992), 1, pp. 117-123 Schink, Bernhard Dimroth, Peter Schink, Bernhard eng Cell suspensions or crude extracts of Malonomonus rubra grown anaerobically on malonate catalyze the decarboxylation of this substrate at a rate of 1.7 - 2.5 pmol . min-' . mg protein-' which is consistent with the malonate degradation rate during growth. After fractionation of the cell extract by ultracentrifugation, neither the soluble nor the particulate fraction alone catalyzed the decarboxylation of malonate, but on recombination of the two fractions 87% of the activity of the unfractionated extract was restored. The decarboxylation pathway did not involve the intermediate formation of malonyl-CoA, but decarboxylation proceeded directly with free malonate. The catalytic activity of the enzyme was completely abolished on incubation with hydroxylamine or NaSCN.<br />Approximately 50 - 65% of the original decarboxylase activity was restored by incubation of the extract with ATP in the presence of acetate, and the extent of reactivation increased after incubation with dithioerythritol. Reactivation of the enzyme was also obtained by chemical acetylation with acetic anhydride. These results indicate modification of the decarboxylase by deacetylation leading to inactivation and by acetylation of the inactivated enzyme specimens leading to reactivation. It is suggested that the catalytic mechanism involves exchange of the enzyme-bound acetyl residues by malonyl residues and subsequent decarboxylation releasing C 0 2 and regenerating the acetyl-enzyme.<br />The decarboxylase was inhibited by avidin but not by an avidin-biotin complex indicating that biotin is involved in catalysis. A single biotin-containing 120-kDa polypeptide was present in the extract and is a likely component of malonate decarboxylase. Hilbi, Hubert Dehning, Irmtraut Malonate decarboxylase of Malonomonas rubra, a novel type of biotin-containing acetyl enzyme Hilbi, Hubert Dimroth, Peter application/pdf 1992 deposit-license 2011-03-24T17:28:08Z Dehning, Irmtraut

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

1992_Hilbi_117_123.pdf 142

Das Dokument erscheint in:

KOPS Suche


Stöbern

Mein Benutzerkonto