Cell Surface-based Enzymatic Conjugation Service

The understanding and manipulation of the cell surface are important topics for fundamental studies of cell behavior and translational research on novel biotechnical applications and therapeutic development. As an industry-leading cell surface engineering services provider, Creative Biolabs has accumulated rich precious experience in practice. With extensive experience and strong foundations, we are capable of providing high-quality cell surface-based enzymatic conjugation services.

Introduction of Cell Surface-based Enzymatic Conjugation

Incorporation of unnatural moieties into the cell surfaces can be achieved by incubating the cells with exogenous enzymes in proper conditions, which can catalyze the enzymatic reaction on the cell surfaces in the presence of the necessary substrates. The enzymes either can recognize the naturally existing substrate on the cell surface and transform it into an unnatural functional group or can recognize a specific sequence introduced by traditional molecular biology methods. Due to the mild reaction conditions which are generally compatible with live cells, covalent bond formation, and substrate specificity, enzyme-mediated engineering of live cell surface provides an excellent opportunity to load a cargo moiety including peptides, proteins, and nanoparticles to the cell surface.

Methods and Applications

• Enzymatic transformation of natural substrates

The introduction of an aldehyde group into the cell surface via enzymatic transformation is an attractive strategy to functionalize the cells. Galactose oxidase can recognize an existing natural monosaccharide, such as the terminal galactose or N-acetylgalactosamine residue, on the cell surface and convert it to the aldehyde group for subsequent modification. Such exoenzymatic strategy is complementary to the periodate oxidation method and useful to identify glycosylation sites of glycoconjugates on the bacterial and mammalian cells. Enzymatic tagging of unnatural chemical functionality to the cell surface can also be achieved by glycosyltransferases, which can conjugate appropriate unnatural sugars to the existing surface glycoforms, expanding the cell-surface carbohydrate repertoire. Siayltransferases and fucosyltransferases are commonly used due to their promiscuous substrate specificity, allowing for the introduction of a broad range of unnatural carbohydrate epitopes onto cells for various applications, such as proteomics, imaging, and control of cell behavior.

• Enzymatic modification using genetically introduced substrates

Modifying the cell surface using this strategy is usually achieved by targeting a specific sequence in a surface-exposed protein, which is useful for cell biology research, in particular for bioimaging. With the action of an enzyme, a synthetic probe could be ligated with the recognition sequence which is expressed in fusion with the protein of interest using a traditional genetic engineering approach. The recognition sequence can be large proteins or small peptides. The protein recognition tags include the SNAP tag, Halo Tag, or ACP tag. However, due to the large size of the protein tag, the tag may have an impact on the folding, function, or trafficking ability of the fusion protein. Comparably, peptide recognition motifs are much more preferable. For example, biotin ligase can conjugate the biotin moiety and a ketone functionalized analog of biotin to the cell surface by recognizing the 15-amino acid consensus sequence in the protein substrate for diverse functionalization of cells.

Fig.1 Cell surface modification by using exogenous enzymes. (Bi, 2018)

Services at Creative Biolabs

Focusing on cell membrane engineering research over years, Creative Biolabs is professional in this field. We have equipped our platform with advanced facilities and accumulated rich experience during the years of practice. With great foundations and excellent scientific staff, we are confident in the quality of our services.

• Comprehensive technologies for customers’ choices
• Proficient technicians to ensure the quality of the services
• High efficiency with preferential price

As a global-leading CRO company, Creative Biolabs aspires to provide every customer satisfying services and we are trying our best to do so. If you are interested in cell surface-based enzymatic conjugation services or other cell membrane engineering services, please don't hesitate to contact us for more information.

Reference

1. Bi, X.; et al. Chemical and enzymatic strategies for bacterial and mammalian cell surface engineering. Chemistry. 2018, 24(32): 8042-8050.