caa a22 4500 469115327 CHVBK 20180323133123.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF00731135 doi (NATIONALLICENCE)springer-10.1007/BF00731135 Effects of site-specific mutations on the enzymatic properties of a sialidase from Clostridium perfringens [Elektronische Daten] [Telse Roggentin, Reinhard Kleineidam, Roland Schauer, Peter Roggentin] Three site-specific mutations were performed in two regions of a sialidase gene fromClostridium perfringens which are known to be conserved in bacterial sialidases. The mutant enzymes were expressed inEscherichia coli and, when measured with MU-Neu5Ac as substrate, exhibited variations in enzymatic properties compared with the wild-type enzyme. The conservative substitution of Arg 37 by Lys, located in a short conserved region upstream from the four repeated sequences common in bacterial sialidase genes, was of special interest, asK M andV max, as well asK i measured with Neu5Ac2en, were dramatically changed. These data suggest that this residue may be involved in substrate binding. In addition to its low activity, this mutant enzyme has a lower temperature optimum and is active over a more limited pH range. This mutation also prevents the binding of an antibody able to inhibit the wild-type sialidase. The other mutations, located in one of the consensus sequences, were of lower influence on enzyme activity and recognition by antibodies. Chapman & Hall, 1992 sialidase (neuraminidase) nationallicence site-specific mutations nationallicence conserved sequences nationallicence enzymatic properties nationallicence Clostridium perfringens nationallicence Roggentin Telse Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut Kleineidam Reinhard Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut Schauer Roland Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut Roggentin Peter Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut Glycoconjugate Journal Kluwer Academic Publishers 9/5(1992-10-01), 235-240 0282-0080 9:5<235 1992 9 10719 https://doi.org/10.1007/BF00731135 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00731135 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Roggentin Telse Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut NATIONALLICENCE 700 1- Kleineidam Reinhard Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut NATIONALLICENCE 700 1- Schauer Roland Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut NATIONALLICENCE 700 1- Roggentin Peter Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr. 40, W-2300, Kiel, Germany aut NATIONALLICENCE 773 0- Glycoconjugate Journal Kluwer Academic Publishers 9/5(1992-10-01), 235-240 0282-0080 9:5<235 1992 9 10719 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer