Streptomyces griseus trypsin (SGT)을 코드하는 sprT 유전자와 그 하류에 존재하는 두 개의 조절 유전자 rsgtR1 및 sgtR2를 동시에 갖고 있는 재조합 벡터 pWHM3-TR1R2를 S. lividans TK24 및 S. griseus IFO 13350에 도입하여, 트립신의 생산성을 더욱 증대시킬 수 있는 배지를 조사하였다. S. lividans TK24/pWHM3-TR1R2의 경우 배양 5일을 기준으로 R2YE에서 가장 높은 생산성(0.74 unit/mL)을 나타냈고, C5/L. (0.66 unit/mL), Livid (0.08 unit/mL), NDSK(0.06 unit/mL) 순으로 나타났다 S. griseus IFO 13350/pWHM3-TR1R2의 경우에는 전반적으로 배양 7일에 트립신 활성이 가장 높았으며, C5/L (1.518 unit/mL), R2YE(1.284 unit/mL), NDSK (0.932 unit/mL), Livid (0.295 unit/mL) 순으로 나타났다. S. griseus IFO 13350/pWHM3-TR1R2를 C5/L 배지에서 7일간 배양한 배양액으로부터 $25%{sim}60%$ ammonium sulfate 침전, CM-sepharose 및 Sp-sepharose column chromatography를 통하여 트립신을 고순도로 정제할 수 있었다. 최종 purification fold는 6.5배, 순수 정제된 트립신의 specific activity는 69,252 unit/mg, 회수율은 1.4%이었다.
The expression vector (pWHM3-TR1R2) for sprT gene encoding Streptomyces griseus trypsin (SGT) followed by two regulatory genes, sgtR1 and sgtR2, was introduced into Streptomyces lividans TK24 and Streptomyces griseus IFO 13350. Various media with different compositions were used to maximize the productivity of SGT in the recombinant trains. he SGT productivity was best when the transformant of S. lividans TK24 was cultivated in R2YE medium (0.74 unit/mL) at 5 days of cultivation. C5/L (0.66 unit/mL) medium also gave a good productivity, but Livid (0.08 unit/mL) and NDSK (0.06 unit/mL) yielded poor productivities. S. griseus IFO 13350/pWHM3-TR1R2 produced SGT by 1.518 unit/mL (C5/L), 1.284unit/mL (R2YE),0.932 unit/mL (NDSK), and 0.295 unit/mL (Livid) at 7 days of cultivation, which was much higher than those from S. lividans TK24/TR1R2. The SGT protein was purified from the culture broth of S. griseus IFO 13350/pWHM3-TR1R2 in C5/L to homogeneity via ammonium sulfate fractionation, and CM-sepharose and SP-sepharose column chromatographies. The specific activity of purified SGT was 69,252 unit/mg, and the final purification fold and recovery yield were 6.5 and 1.4%, respectively.
