Creative Biolabs provides the custom neocarzinostatin library construction service by our innovative Hi-Affi™ platform. With this advanced phage display platform, our experts can offer high diversity and quality libraries for selecting high affinity target-binders.
Neocarzinostatin (NCS), a macromolecular enediyne-binding chromoprotein isolated from Streptomyces carzinostaticus, is clinically used as an antitumor agent. NCS is a most studied member of macromolecular antibiotic family, which contains a variety of protein antitumor antibiotics, such as actinoxanthin (AXN), macromomycin (MCR), kedarcidin (KED) and C-1027 protein. These proteins are close homologues to NCS and all bind tightly to their own specific chromophore. Structurally, NCS is compounded by two parts, a non-protein labile chromophore and a 113 amino acid protein. The chromophore is extremely unstable, but its enediyne ring possesses potent DNA cleaving property, which contributes to the antitumor and antibiotic activity of chromophore. The protein part is consisted of seven β-strands in two sheets forming a β-sandwich, with a topology similarity to the immunoglobulin fold. Simultaneously, the protein structure indicates a deep crevice formed by two loops, which structurally like the CDR1 and CDR3 of an antibody, can bind to the organic chromophore tightly and non-covalently with high affinity. This protein naturally plays a role to protect the unstable chromophore and release it to the target DNA.
According to its role in natural conditions, the protein part of NCS has been considered as a scaffold for potential drug delivery. By random substitution or site mutation toward the binding crevice, NCS scaffold libraries can be generated and selected for the recognition of other anti-tumoral chromophores or small molecule drugs to facilitate or diversify the targeted delivery. Relevant researches have achieved specific testosterone binders from NCS mutation libraries and lysozyme binder by transferring CDR3 of anti-lysozyme camel VHH to the corresponding loop of NCS. In this way, NCS may be adopted as a drug delivery vehicle by conferring new binding specificities to its protein scaffold, which can raise considerable interest from chemical, biological and medical perspectives.
Scientists of Creative Biolabs have generated various scaffold libraries through our proprietary Hi-Affi™ phage display platform. This novel platform relies on the original phage display method, which is an exogenous gene expression method through fusing the target genes to bacteriophage coat proteins then displaying on the phage surfaces to select specific binders. Moreover, the platform has also coupled with trimer codon technology and NNK method. By this Hi-Affi™ platform, our scientists can overcome the issue of low library diversity, and expand the range of the library diversity to more than 1010 with 100% precise mutant.
Creative Biolabs has years of research and development experience in the field of phage library construction. The company is committed to offering services of industry leading caliber with our professional experts, advanced technology, high quality and reliable products, yet with the most competitive price for customers all over the world.
Fig. 1 Structure of the antitumor protein-chromophore complex neocarzinostatin. (PDB ID: 1NCO )