EXPRESSION AND PURIFICATION OF MOUSE SULFATED GLYCOPROTEIN-2

SGP-2 is a glycosylated protein initially found in the testes of rats. The cDNA of SGP-2 isolated from mouse testis was transcribed in vitro using SP6 RNA polymerase and the transcribed RNA product was translat ed in vitro using rabbit reticulocyte. The molecular weight of the in vitro translated SGP-2 vr;as 41,000, which is 10,000 less than that ca lculated based on the nucleotide sequence. We proposed that there is a n internal signal for translation in front of methionine residue,at 92 . Based on these results, it was conjectured that SGP-2 could be regul ated translationally. The cDNA of SGP-2 was also expressed in E. coil using T7 RNA polymerase system. SGP-2 cDNA was fused to the gene of gl utathione-S-transferase, and the fusion protein was purified from E. c oli extracts in a single step using affinity chromatography.