This article was originally published in the June 2015 edition of Matreya’s Newsletter for Glyco/Sphingolipid Research (PDF).

Cayman’s biotinylated sphingolipids take advantage of the strong and specific interaction of biotin with streptavidin/avidin for use in sphingolipid research. Each contains a biotin label attached to the amine of the sphingosine moiety via a hexanoic acid linker, which maintains the sphingolipid’s natural properties and enables a more natural protein interaction.

Employing common streptavidin/avidin biochemical methodologies, these probes are extremely useful for binding studies and for toxin detection. For example, the inhibitor 2 of protein phosphatase 2A (I2PP2A) was identified as a ceramide binding protein using biotin-labeled ceramide.¹ I2PP2A-ceramide binding decreases the association between PP2A and the inhibitor, preventing the inhibition of PP2A activity in vitro. Direct interaction of I2PP2A with ceramide plays important biological roles via the regulation of PP2A activity and signaling, which in turn controls ceramide-mediated degradation of c-Myc, the multifunctional transcription factor that drives the multiple synthetic functions necessary for rapid cell division while at the same time inhibiting expression of genes with antiproliferative functions. Biotin-labeled ganglioside analogs have also been used to detect E. coli enterotoxin on streptavidin-coated ELISA plates.² Enterotoxigenic E. coli is a pathogenic form of bacteria that is a serious threat to health and food safety around the world. Thus, the detection of enterotoxins is of critical importance in preventing foodborne diseases.

1. Mukhopadhyay, A., Saddoughi, S.A., Song, P., et al. Direct interaction between the inhibitor 2 and ceramide via sphingolipid-protein binding is involved in the regulation of protein phosphatase 2A activity and signaling. FASEB J. 23(3), 751-763 (2009).

2. Pukin, A.V., Florack, D.E.A., Brochu, D., et al. Chemoenzymatic synthesis of biotin-appended analogues of gangliosides GM2, GM1, GD1a and GalNAc-GD1a for solid-phase applications and improved ELISA tests. Org. Biomol. Chem. 9(16), 5809-5815 (2011).