With the great potential of single domain antibody (sdAb) in the application of therapeutic and diagnostic, Creative Biolabs has developed a series of sdAb conjugation services to meet our client specific needs. Based on years of biotinylation experience, Creative Biolabs has built a unique technical platform named as BtAP-Tag® that can provide custom in vivo and in vitro sdAb labeling options through biotinylation.
Biotinylation is the process of covalently attaching biotin to a protein, nucleic acid or other molecule. The goal of biotinylation is to label the protein of interest based on the premise that without any interference to the overall biological performance of antibodies. Biotin-avidin affinity is at least one million times higher than that of antigen-antibody binding which has the strongest affinity in nature. Therefore, the biotin-avidin system has been widely used in immunodiagnostic techniques. Due to the small size of biotin (MW = 244.31 g/mol), it does not affect the natural function of the protein. So it also has advantages of high affinity, high specificity, and high sensitivity in the use of many areas of biotechnology.
Single domain antibodies (sdAbs) are antibody fragment consisting of a single monomeric variable antibody domain, derived from the heavy-chain-only antibodies produced by camelids or sharks, or the specific developed human VH and VL domain. Compared with conventional antibody, sdAbs have several advantages for biotechnological applications thanks to their unique properties of size (15 kDa), stability, solubility, and expression yield. In this case, the sdAb biotinylation would be a meaning tool for the development of sdAb research.
Fig.1 SdAb and biotin.
On our unique biotinylation platform, biotin holoenzyme synthetase is an enzyme which can select biotinylated E.coli biotin carboxyl carrier protein naturally. Biotin acceptor peptide serves as an in vivo substrate according to fuse with the target sdAb of interest. In the meantime, a specific bacterial expression vector is employed which is feasible for the expression of target sdAb fused with biotin acceptor peptide and also biotin holoenzyme synthetase gene under a bacterial operon. Based on the efficient vector, the fully biotinylated sdAb can be co-expressed with biotin acceptor peptide.
Meanwhile, scientists from Creative Biolabs can offer a series of biotin labeling methods to meet our clients’ demands.
Table 1. Labeling methods
|Enzymatic biotinylation||Primary amino biotinylation|
|Sulfhydryl biotinylation||Carboxyl biotinylation|
|Glycoprotein biotinylation||Oligonucleotide biotinylation|
With years of extensive experience and the advanced platform, Creative Biolabs is pleased to offer the best service and the most qualified products to meet the specific needs of our customers. If you are interested in our single domain antibody biotinylation service, please do not hesitate to inquire our experts for more details