Open AccessPurification and characterization of cyanophycin and cyanophycin synthetase from the thermophilic Synechococcus sp. MA19
Author(s) -
Hai Tran,
OppermannSanio Fred Bernd,
Steinbüchel Alexander
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb08849.x
Subject(s) - size exclusion chromatography , thermophile , molecular mass , biochemistry , gel electrophoresis , polyacrylamide gel electrophoresis , chromatography , synechococcus , chemistry , arginine , sodium dodecyl sulfate , aspartic acid , cyanobacteria , amino acid , enzyme , biology , bacteria , genetics
The biosynthesis and accumulation of cyanophycin in the thermophilic cyanobacterium Synechococcus sp. MA19 were studied. By growing the cells in a 80‐l closed tubular photobioreactor under controlled conditions, the cells accumulated cyanophycin amounting up to 3.5% of the dry cell matter. The cyanophycin was purified and chemical analysis showed that it was composed of arginine and aspartic acid occurring at a molar ratio of 1:0.9. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed a broad distribution of the apparent molecular masses ranging from 20 to 130 kDa with a maximum at 50 kDa. During a three‐step purification procedure involving ion exchange chromatography and gel filtration, the cyanophycin synthetase from strain MA19 was purified 144‐fold to electrophoretic homogeneity. It consisted of only one single type of subunit exhibiting an apparent molecular mass of 130 kDa. The enzyme catalyzed the polymerization of arginine and aspartate at elevated temperatures and was even active at 80°C.