Antibody-Onconase & RapLR1 Fusion Protein

With years of experience, Creative Biolabs offers customized antibody-onconase & RapLR1 fusion protein with first-class technology and platform. Our optimized fusion expression strategy will promote the development of innovative cancer treatments.

Onconase & RapLR1

Onconase is an amphibian ribonuclease found in oocytes of the leopard frog. It is a member of the pancreatic ribonuclease (RNase A) protein superfamily which targets RNA substrates with a sequence preference for uracil and guanine nucleotides. It has been extensively studied for its potent antitumor properties, as it has a naturally high selectivity for cancer cells. The clinical trials of onconase have shown that it has low immunogenicity and very little nonspecific toxicity. The mechanism of onconase to perform tumor cytotoxicity selectively is via cleaving siRNA molecules to interfere with the RNA pathway. As a result, the NF-кB pathway can interfere. At present, onconase is in Phase I clinical study for the treatment of anogenital warts. Rana pipens liver RNase1 (RapLR1), a close homolog of onconase, offers an advantage over other amphibian ribonucleases because it retains its ribonucleolytic and cytotoxic activity without post-translational modifications of the N-terminus (the active site).

Fig.1 Mechanism of action. In cancer cells, onconase-induced intracellular RNA đegradation triggers several biological effects simultaneously including the induction of the "intrinsic" (mitochondria) pathway of apoptosis and modulation of the expression of several key cell cycleregulatory factors.

Antibody-onconase & RapLR1 Fusion Protein

In early studies, antibody-onconase chemical conjugates were used to treat B-cell lymphoma xenografts effectively in immunodeficient mice, demonstrating potency comparable to immunotoxins without mediating nonspecific toxicity. Second-generation (fusion protein) immunoRNases have proven to be promising fusion proteins for targeting various malignancies. Rana pipens liver RNase1 (RapLR1) dimeric fused to the N-terminus of an anti-CD22 scFv humanized antibody was found to inhibit protein synthesis in CD22⁺ tumor cells. The dimer exhibited superior cytotoxicity over the monovalent immunoRNase variants and chemical conjugates, possibly as a result of increased avidity leading to increased antigen-immunoRNase binding and internalization.

Fig.2 Purification of monomeric and dimeric RNase-scFv fusion proteins. Schematic representation of expressed monomeric rapLRI-scFv 1.110 and dimeric rapLRI-diabody 1.111 fusion proteins. (Krauss, 2005)

With our advanced technology platforms and experienced scientists, Creative Biolabs is committed to helping you develop antibody-onconase & RapLR1 fusion protein in a timely and cost-effective manner. Our high-quality services and products will contribute greatly to the success of your projects. Please feel free to contact us for more information if you are interested in the antibody-onconase & RapLR1 conjugate.

Reference

1. Krauss, J.; et al. Efficient killing of cd22⁺ tumor cells by a humanized diabody-rnase fusion protein. Biochemical & Biophysical Research Communications. 2005, 331(2), 595-602.