Purification and properties of α-1,4-glucan phosphorylase from the red seaweed Gracilaria sordida (Gracilariales) |
| |
Authors: | Shukun Yu,Marianne Pedersé n |
| |
Affiliation: | Dept of Physillogial Botany, Univ. of Uppsala, Box 540, S-751 21 Uppsala, Sweden. |
| |
Abstract: | α-1,4-Glucan phosphorylase (EC 2.4.1.1) from the red seaweed Gracilaria sordida (Harv.) W. Nelson was adsorbed onto starch-Sepharose 6B and Sephacryl S-300 under specified conditions. The algal enzyme was purified to homogeneity by these two steps. A molecular weight of 97.4 kDa was observed on SDS-polyacrylamide gel electrophoresis under reducing conditions, while the native molecular weight was 240 kDa asrevealed by 8-25% native gradient gel electrophoresis or 245 kDa by gel filtration. The pI of the enzyme was 5.4. It had a Km of 227, 264, 285, and 453 μg ml-1, respectively, towards glycogen, amylopectin, amylose, and maltodextrin. The enzyme activity was inhibited by cyclohexaamylose, ADP-glucose, and UDP-glucose. In contrast to other plant sources, cell-free extracts of G. sordida contained only one form of phosphorylase. |
| |
Keywords: | ADP-glucose α-1,4-glucan phosphorylase Gracilaria sordida Sephacryl gel UDP-glucose |
|
|