Babaeipour Valiollah, Vahidi Hossein, Alikhani Shamila, Ranjbari Javad, Alibakhshi Abbas, Tabarzad Maryam
Department of Biotechnology, Malek Ashtar University of Technology, Tehran, Iran.
Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Protein Pept Lett. 2018;25(11):980-985. doi: 10.2174/0929866525666181019150657.
IGF-I as a human growth factor produced in Escherichia coli is a single, non-glycosylated, polypeptide chain containing 70 amino acids and having a molecular mass of 7.6 kDa. Up to now, E. coli expression system has been widely used as the host to produce rhIGF-1 with high yields. Acyl Homoserine Lactones (AHLs) are intercellular signaling molecules used in quorum sensing by Gram-negative bacteria. Quorum sensing is a cell density-dependent gene regulation process that allows bacterial cells to express specific genes only when signaling molecules reach the sufficient concentration.
For the first time, this study focuses on the N-hexanoyl-L- Homoserine Lactone (HHL) activity on increasing the cell growth and rh-IGF-1concentration in batch culture of E. coli.
The maximum production of rhIGF-I was previously optimized in 32y culture medium at 32°C with 0.05 mM IPTG as inducer and 10 g/l glucose concentration. Under this condition, different amounts of HHL (0.001 µg/ml, 1 µg/ml, and 100µg/ml) were evaluated as an inducer for IGF-1 production.
Generally, with increasing of HHL concentration, an increase in dry cell weight (2.45 mg/ml to 4.63 mg/ml) and IGF-I expression level (0.4 mg/ml to 0.77 mg/ml) was observed.
HHL or other types of AHLs can be considered as protein production inducer in bacterial expression systems through the quorum sensing pathways.
作为一种在大肠杆菌中产生的人类生长因子，胰岛素样生长因子 -I（IGF-I）是一条单一的、非糖基化的多肽链，包含70个氨基酸，分子量为7.6 kDa。到目前为止，大肠杆菌表达系统已被广泛用作宿主，以高产率生产重组人胰岛素样生长因子-1（rhIGF-1）。酰基高丝氨酸内酯（AHLs）是革兰氏阴性菌群体感应中使用的细胞间信号分子。群体感应是一种细胞密度依赖性基因调控过程，它使细菌细胞仅在信号分子达到足够浓度时才表达特定基因。
本研究首次聚焦于N-己酰基-L-高丝氨酸内酯（HHL）在大肠杆菌分批培养中对细胞生长和rh-IGF-1浓度增加的活性。
先前已在32y培养基中，于32°C、以0.05 mM异丙基-β-D-硫代半乳糖苷（IPTG）作为诱导剂、葡萄糖浓度为10 g/l的条件下对rhIGF-I的最大产量进行了优化。在此条件下，评估了不同量的HHL（0.001 µg/ml、1 µg/ml和100 µg/ml）作为IGF-1生产的诱导剂。
一般来说，随着HHL浓度的增加，观察到干细胞重量增加（从2.45 mg/ml增加到4.63 mg/ml）和IGF-I表达水平增加（从0.4 mg/ml增加到0.77 mg/ml）。
HHL或其他类型的AHLs可通过群体感应途径被视为细菌表达系统中的蛋白质生产诱导剂。
