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Cell Penetrating Peptide (CPP)–Modified Liposomal Nanocarriers for Intracellular Drug and Gene Delivery
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
TAT peptide (TATp) remains the most frequently used CPP for drug delivery purposes. TAT is transcriptional activator protein encoded by human immunodeficiency virus type 1 (HIV-1).47 TAT-mediated transduction was first utilized in 1994 for the intracellular delivery of variety of cargos such as β-galactosidase, horseradish peroxidase, RNase A, and domain III of Pseudomonas exotoxin A in vitro.48 In vivo transduction using TAT peptide (37–72)-conjugated to β-galactosidase resulted in protein delivery to different tissues such as the heart, liver, spleen, lung, and skeletal muscle. Next, attempts were made to narrow down to the specific domain responsible for transduction. For this, synthetic peptides with deletions in the α-helix domain and the basic cluster domain were prepared for investigating their translocation ability.49 The whole basic cluster from 48 to 60 residues was found accountable for membrane translocation because any deletions or substitutions of basic residues in TAT (48–60) reduced the cellular uptake property. Rothbard et al.50 studied TAT (48–57) by deletion analysis. They found that deletion of Gly-48 did not affect the transduction efficiency, whereas deletions of Lys-50,51, Arg-55–57 and Gln-54 markedly reduced transduction efficiencies. Therefore, the minimal transduction domain was assigned to TAT (49–57) residues. The commonly studied transduction domain of TAT (TAT PTD) extends from residues 47–57: Tyr-Gly-Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg that contain six arginines (Arg) and two lysine residues.51
Production of recombinant lethal factor of Bacillus anthracis in Bacillus subtilis
Published in Preparative Biochemistry & Biotechnology, 2021
Mahboobeh Gholami, Majid Moghbeli, Farshid Kafilzadeh, Mohammad Kargar, Mariam Bikhof Torbati, Ashkan Tavizi, Sally Bellevile, Javad Hatami, Zahra Eslami
Nowadays due to the high cancer rate, high medical cost, side effects of many common treatments, and resistance to anticancer treatments in patients with advanced solid tumors, scientists are looking for new ways for cancer treatment. The engineered bacteria usage has been introduced as a new way of cancer therapy, including the direct antitumor effects or transmission of agents that have these effects.[33–35] One of the bacterial parts that can be engineered is bacterial toxin. The engineered bacteria toxin can specifically target tumors and create toxicity in tumor cells.[7] These toxins can alter cellular processes that control the proliferation, apoptosis and differentiation associated with cancer and kill cancer cells. Several studies have reported manipulation of some bacterial toxins to specifically target tumor cells such as Clostridium diffcile toxin, Shiga-like toxin 1, Pseudomonas exotoxin A, Pertussis toxin etc. The similar effect has been observed about manipulation of Bacillus anthracis lethal toxin.[36,37] The Bacillus anthracis toxin consists of three polypeptides: a cellular receptor binding component – PA and two enzymatic moieties – EF and lef gene. PA binds to cell surface and then it inserts lef gene and EF subunits of toxin into the cell and these three proteins are not toxic individually.[38] In the recent years, the PA mutagenesis has been investigated to particularly target tumor cells. The resulting PA was highly potent against tumors with high uPA expression. Due to the increased expression of the uPA on cancer cells, it can be employed to target cancerous tumors.[16,39]