- Tytuł:
- Amino acid substitutions of His296 alter the catalytic properties of Zymomonas mobilis 10232 levansucrase
- Autorzy:
-
Li, Shu
Chen, Ming
Li, Gang
Yan, Yong
Yu, Hai
Zhan, Yu
Peng, Zi
Wang, Jin
Lin, Min - Powiązania:
- https://bibliotekanauki.pl/articles/1040841.pdf
- Data publikacji:
- 2008
- Wydawca:
- Polskie Towarzystwo Biochemiczne
- Tematy:
-
Zymomonas mobilis
His296
levansucrase
levan
transfructosylation activity
hydrolysis activity - Opis:
- His296 of Zymomonas mobilis levansucrase (EC 2.4.1.10) is crucial for the catalysis of the transfructosylation reaction. The three-dimensional structures of levansucrases revealed the His296 is involved in the substrate recognition and binding. In this study, nine mutants were created by site-directed mutagenesis, in which His296 was substituted with amino acids of different polarity, charge and length. The substitutions of His296 with Arg or Trp retained partial hydrolysis and transfructosylation activities. The positively charged Lys substitution resulted in a 2.5-fold increase of sucrose hydrolysis. Substitutions with short (Cys or Ser), negatively charged (Glu) or polar (Tyr) amino acids virtually abolished both the activities. Analysis of transfructosylation products indicated that the mutants synthesized different oligosaccharides, suggesting that amino acid substitutions of His296 strongly affected both the enzyme activity and transfructosylation products.
- Źródło:
-
Acta Biochimica Polonica; 2008, 55, 1; 201-206
0001-527X - Pojawia się w:
- Acta Biochimica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł