In this study, Rhizomucor miehei -1,3-1,4-glucanase gene was expressed under the regulation of AOX1 promoter in the Pichia pastoris expression system, and the clone providing the highest production level was determined. The codon-optimized gene was ligated into expression vector pPICZA and transferred into competent P. pastoris KM71H cells. Thirty transformants were selected from plates containing different concentrations of zeocin and cultured in test tubes for protein production. Glucanase enzyme activities in supernatant samples were measured and ten clones showing the highest glucanase activity were determined. The proteins in supernatant samples were also analyzed by SDS-PAGE and the glucanase enzyme was observed in 2 bands, approximately 34 and 38 kDa. Protein production was performed for 72 hours in 200 mL induction medium (BMMY) with the clone providing the highest glucanase enzyme production and the recombinant glucanase enzyme was purified by Ni-NTA affinity chromatography. After purification, it was determined that the analyzed clone reached 796 mg/L glucanase production level. SDS-PAGE analysis of samples from each step of the purification procedure showed that the two protein bands also observed in the supernatant samples represent glucanase enzyme.
Gıda endüstrisinde enzimler her türlü işleme ve üretim proseslerinde uygulama alanı bulan biyolojik katalizörlerdir. Süt işlemeden meyve suyu üretimine, et işlemeden ekmek üretimine kadar gıda sanayinin çeşitli alanlarında yaygın olarak ihtiyaç duyulan enzimlerden biri lipazlardır. Bu çalışmada, kodon optimize edilmiş Geobacillus stearothermophilus lipaz enzimini kodlayan genin, Pichia pastoris ekspresyon sisteminde güçlü ve indüklenebilir bir promotor olan AOX1 promotoru içeren pPICZA ekspresyon vektörü kullanılarak ekspresyonu yapılmış ve en yüksek lipaz enzimi üretimi gösteren klon belirlenmiştir. Belirlenen klon ile 400 mL indüksiyon besiyerinde 72 saat boyunca üretim gerçekleştirilmiş ve toplanan süpernatant örneğinde enzim aktivitesi, toplam protein ve SDS-PAGE analizi gerçekleştirilmiştir. Rekombinant lipaz enzimi Ni-NTA afinite kromatografisi ile saflaştırılmıştır. Saflaştırma işleminin her aşamasından alınan örneklerde SDS-PAGE analizi yapılmış ve her aşamada elde edilen örneklerde saflaştırma verimi hesaplanmıştır. Saflaştırma işleminden sonra analiz edilen örnekte, en yüksek üretim gösteren klonun 25.02 mg L-1 lipaz üretim seviyesine ulaştığı belirlenmiştir.
Tilapia piscidin 4 (TP4), a cationic antimicrobial peptide, is recognized for its diverse biological roles, including antibacterial, wound-healing, and anticancer properties. Herein, the codon-optimized sequence of TP4 peptide was expressed using the pPICZαA expression vector containing the AOX1 promoter, a strong and inducible promoter, in the Pichia pastoris KM71H expression system. Recombinant TP4 peptide was purified by Ni-NTA affinity chromatography. After purification, the anticancer activity of TP4 was assessed in HUH-7 hepatocellular carcinoma cells, and the underlying mechanisms were determined. In the present study, it was demonstrated for the first time that recombinant TP4 displayed strong anticancer activity in the human HUH-7 cell line. The TP4 antimicrobial peptide can be used as a competitive candidate for the treatment of cancer cells due to its anticancer effects.
