TY - JOUR
T1 - Structure/function relationship studies on the T/S residues 173-177 of rat ODC
AU - Matés, José Manuel
AU - Del Valle, Alicia E.
AU - Urdiales, José Luis
AU - Coleman, Catherine
AU - Feith, David
AU - Olmo, M. Teresa
AU - Pegg, Anthony
AU - Sánchez-Jiménez, Francisca
N1 - Funding Information:
This work has been granted by CICYT PB94-1474 and SAF98-0150 (Ministry of Education, Spain) and PAI-3218 (Junta de Andalucı́a, Spain), and by NATO CRG95-CRG950677. JLU and AE receive grants from the Ministry of Education (Spain). Thanks are due to undergraduate students J.M. Martı́nez-Moreno, J.A. Cornejo and E. Pozo for help during experiments.
PY - 1998/7/28
Y1 - 1998/7/28
N2 - A well-conserved T/S cluster was detected among vertebrate ornithine decarboxylase by computer analysis (E. Viguera, O. Trelles, J.L. Urdiales, J.M. Mates, F. Sanchez-Jimenez, Trends Biochem. Sci. 19 (1994) 318-319). In the present report we studied the role of these residues (173, 176 and 177 in rat ornithine decarboxylase (ODC)) in enzymic activity and stability by in vitro expression, kinetic characterization and in vitro degradation of site-directed mutants. These T/S residues are substituted by a D/E-enriched fragment in other lower eukaryotic ODCs. The substitution of the T/S-enriched fragment (TLKTS) of rat ODC by the negative charged fragment of T. brucei ODC (KVEDC) did not affect protein stability, but increased K(m) values of the mutant enzyme. The substitution of the T/S residues by alanine also has a similar effect on rat ODC kinetic values. However, results indicate that polarity of the fragment must be an important factor for protein conformation, since the latter mutant, having no T/S or D/E residue in the fragment (ALKAA), showed reduced stability in vitro. Copyright (C) 1998 Elsevier Science B.V.
AB - A well-conserved T/S cluster was detected among vertebrate ornithine decarboxylase by computer analysis (E. Viguera, O. Trelles, J.L. Urdiales, J.M. Mates, F. Sanchez-Jimenez, Trends Biochem. Sci. 19 (1994) 318-319). In the present report we studied the role of these residues (173, 176 and 177 in rat ornithine decarboxylase (ODC)) in enzymic activity and stability by in vitro expression, kinetic characterization and in vitro degradation of site-directed mutants. These T/S residues are substituted by a D/E-enriched fragment in other lower eukaryotic ODCs. The substitution of the T/S-enriched fragment (TLKTS) of rat ODC by the negative charged fragment of T. brucei ODC (KVEDC) did not affect protein stability, but increased K(m) values of the mutant enzyme. The substitution of the T/S residues by alanine also has a similar effect on rat ODC kinetic values. However, results indicate that polarity of the fragment must be an important factor for protein conformation, since the latter mutant, having no T/S or D/E residue in the fragment (ALKAA), showed reduced stability in vitro. Copyright (C) 1998 Elsevier Science B.V.
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U2 - 10.1016/S0167-4838(98)00090-9
DO - 10.1016/S0167-4838(98)00090-9
M3 - Article
C2 - 9675257
AN - SCOPUS:0032575257
SN - 0167-4838
VL - 1386
SP - 113
EP - 120
JO - Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology
JF - Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology
IS - 1
ER -