Creative Biolabs provides the high quality CTLD library construction service by our innovative Hi-Affi™ phage display platform. With years of experience in the field of scaffold library construction, our scientists are confident in generating high affinity and diversity libraries for selection of the most potential binders for targets of interest.
C-type lectin-like domain (CTLD) is termed for a novel compact globular structure confirmed in the carbohydrate-recognition domain (CRD) of the Ca2+-dependent (C-type) lectins. This is often used interchangeably with C-type lectin domain (abb. CTLD as well), which lead to some confusions. Adopting the broadest definition, C-type lectin-like domain (CTLD) refers to protein domains that are homologous to the CRDs of the C-type lectins, or which have structure resembling with the prototypic C-type lectin domain (Zelensky and Gready 2005).
C-type lectin domains (CTLDs) are known as a protein scaffold composed of an oligomeric structure and multiple interactions, which endowing them with the ability to form macromolecular complexes with high avidity. Proteins containing C-type lectin domains (CTLDs) have formed a superfamily includes more than a thousand identified members from various animal species. It represents a large group of extracellular Metazoan proteins with diverse functions. The CTLDs share a conserved structural core, which is characterized by a double-loop structure. The overall domain of CTLD is a loop, the second loop (also known as the long loop region) locates within the domain. The structure also consists of an antiparallel β-sheet is formed through the nearby N- and C-terminal β strands, another three β stands formed β-sheet and two flanking α helices. The whole structure is stabilized by two highly conserved disulfide bridges located at the bases of the loops, as well as a set of conserved hydrophobic and polar interactions.
The loop region of CTLDs is recognized as a conserved structural scaffold, which contributes to a wide range of interactions between CTLDs and several types of carbohydrates, lipids and proteins. For instance, tetranectin is a homo-trimeric protein comprising a CTLD and a coiled-coil trimerization module. The trimerizing coiled-coil region seems to support an avidity effect, which can ideally come into place in the case of the similarly homo-trimeric target protein. It is also possible to modify the carbohydrate specificity of CTLDs which may result in new carbohydrate affinity.
Hi-Affi™ platform, a proprietary technology of Creative Biolabs, is an improved phage display system using the trimer codon technology and NNK method. Compared with traditional phage display technology, 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, Hi-Affi™ phage display technology can improve the library affinity and diversity to obtain 100% precise mutant library construction with over 1010 diversity. This technology is suitable for screening and selecting the high affinity protein or peptide targets.
Creative Biolabs guarantees the reliability of each service through our strict quality control standards. Meanwhile, customers will receive the report of sample test and library inspection to follow the project schedule and quality in time.
Fig. 1 Structure of the calcium free form of the C-type lectin-like domain of tetranectin. (PDB ID: 1RJH)