Recombinant human extracellular superoxide dismutase produced in milk of transgenic rabbits.
Expression of human extracellular superoxide dismutase (EC-SOD), a glycosylated, tetrameric metalloprotein, was targeted to the lactating mammary gland of transgenic rabbits. Efficient expression of the recombinant whey acidic protein/ec-sod gene was achieved and up to 3 mg ml-1 of the enzyme was secreted into the milk. Rabbit milk-produced recombinant EC-SOD was primarily found in the whey and purified by a two-step chromatographic method. To evaluate the rabbit milk-produced human EC-SOD, comparisons with native and Chinese hamster ovary cell (CHO)-produced EC-SOD were performed. All proteins were tetrameric and N-glycosylated. The behaviour on SDS-PAGE and size-exclusion chromatography indicated that the masses, and thereby the extent of post-translational modification of the proteins was similar. The monosaccharide composition of both recombinant EC-SOD variants was analysed and indicated similarities in the attached N-glycans on the two proteins. Furthermore, the peptide maps of the three EC-SOD variants revealed that all proteins had similar polypeptide backbones.
Strömqvist
M
M
Astra Hässle AB, Umeå, Sweden.
Houdebine
M
M
Andersson
J O
JO
Edlund
A
A
Johansson
T
T
Viglietta
C
C
Puissant
C
C
Hansson
L
L
D000818:Animals; D030801:Animals, Genetically Modified; D016466:CHO Cells / Q000378:metabolism; D002845:Chromatography / Q000379:methods; D006224:Cricetinae; D005260:Female; D006031:Glycosylation; D006493:Heparin / Q000378:metabolism; D006801:Humans; D008892:Milk / Q000201:enzymology*; D010455:Peptides / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D010455:Peptides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D006493:Heparin; D013482:Superoxide Dismutase