Helix pomatia Lectin (HPA) - Texas Red

Helix pomatia agglutinin (HPA) is isolated from edible snail by affinity chromatography. It is a lectin secreted by albumen gland that produces perivitelline fluid and is composed of protein and polysaccharide complexes that coat each fertilized egg. HPA has the property to aggregate bacteria such as group C streptococci and Listeria monocytogenes, and ability to bind to the surface of herpes virus. This lectin has been shown to agglutinate blood group A red cells but not those of B or O. HPA binds GalNAc present on the Tn antigen, but not its galactosylated form, with potential to also recognize the T antigen. HPA has specificity for GalNAc and GlcNac, with its main inhibitor being N-acetylgalactosamine. This lectin consists of six identical protein subunits, each containing one intra-chain disulfide bond and a carbohydrate binding site, with a total molecular weight of 79 kDa. HPA is a glycoprotein with roughly 7% carbohydrate content and presence of different glycoforms. The structure of HPA brings two sets of three binding sites on opposite hydrophilic and charged faces of the molecule in a construction that allows two bacteria to be bound at the same time, promoting aggregation and efficient protection of snail eggs. HPA has been successfully used as an indicator of metastatic spread in several epithelial neoplasms including breast, colorectum, gastric, prostate and oesophageal cancers. It has also been used in cell binding studies for urinary bladder carcinoma cell lines and an osteogenic sarcoma cell line.

Texas Red is a red-fluorescent dye and when bound to HPA can show the binding pattern of this lectin in cellular imaging applications. There is very little overlap between the emission spectra of Texas Red and FITC making this combination ideal for dual-labeling experiments. Rhodamine dyes, such as Texas Red, are more photostable and less sensitive to pH change when compared to other dyes such as fluorescein.

Specifications:
Source: Helix pomatia (Roman Snail)
Activity: Specific to blood group A (A1 and A2).
Carbohydrate Specificity: GalNAc, GlcNac
Inhibitory Carbohydrate: N-Acetylgalactosamine
Divalent Ions Required: None required
Conjugation: Texas Red

Storage and Stability:
Store frozen at -20°C in amber vials in appropriate aliquot sizes. Avoid freeze thaw cycles. Can be stored at 2-8°C for short term use.

References
Dwek, M. V., Ross, H. A., Streets, A. J., Brooks, S. A., Adam, E., Titcomb, A., Woodside, J. V., Schumacher, U., & Leathem, A. J. (2001). Helix pomatia agglutinin lectin-binding oligosaccharides of aggressive breast cancer. International journal of cancer, 95(2), 79–85. https://doi.org/10.1002/1097-0215(20010320)95:2<79::aid-ijc1014>3.0.co;2-e

Rambaruth, N. D., Greenwell, P., & Dwek, M. V. (2012). The lectin HELIX POMATIA Agglutinin Recognizes O-GlcNAc Containing Glycoproteins in human breast cancer. Glycobiology, 22(6), 839–848. https://doi.org/10.1093/glycob/cws051

Sanchez, J. F., Lescar, J., Chazalet, V., Audfray, A., Gagnon, J., Alvarez, R., Breton, C., Imberty, A., & Mitchell, E. P. (2006). Biochemical and structural analysis of Helix pomatia agglutinin. A hexameric lectin with a novel fold. The Journal of biological chemistry, 281(29), 20171–20180.
https://doi.org/10.1074/jbc.M603452200

Schumacher, U., Mitchell, B. S., Brooks, S. A., Delpech, B., & Leathem, A. J. (1996). Does the lectin Helix pomatia agglutinin bind to hyaluronic acid in breast and colon cancer?. Acta histochemica, 98(4), 435–440.
https://doi.org/10.1016/s0065-1281(96)80010-9

Properties
Shelf life: 2 yearsStorage Temperature: -20°CHazmat Ship: Non-HazardousAppearance color: RedAppearance form: LiquidMolecular Weight: 79 kDaAbbreviation (Lectins Only): HPASource: SnailCarbohydrate Specificity: N-AcetylgalactosamineConjugate/Tag/Matrix: Texas RedInhibitory Carbohydrate: N-AcetylgalactosamineFluorescence: ReDivalent Ions: None RequiredExcitation: 595 nmMitogenic Activity: NoEmission: 615 nm