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Streptavidin

Streptavidin is a biotin-binding protein found in the culture broth of the bacterium Streptomyces avidinii. Streptavidin binds 4 moles of biotin per mole of protein with a high affinity virtually unmatched in nature. Streptavidin lacks carbohydrate side chains present on avidin and has an isoelectric point nearer to neutrality where most useful biological interactions occur (pI of 5-6 vs 10 for avidin). As a result, streptavidin frequently exhibits lower levels of non-specific binding than does avidin when the proteins are used in applications relying upon the formation of avidin/biotin complexes. Streptavidin is readily soluble in water or buffers. There is a tendency for lyophilized streptavidin to aggregate when it is re-dissolved in water or other low ionic strength buffers at neutral or acidic pH. In ELISA-based diagnostic systems, antibodies directed against a particular antigen may be covalently attached to reporter enzymes. Antigens are then quantitated by enzymatic assay after binding to these conjugated molecules. Unfortunately, the precise conditions for accomplishing such covalent attachments must be determined individually for each antibody/reporter combination, and often result in significant loss of either the enzymatic activity of the reporter enzyme or the binding functions of the antibodies. Streptavidin finds utility in these systems because antibody molecules are easily modified by the covalent attachment of derivatives of biotin with little or no loss in the ability of the antibody molecules to bind their antigens. These biotinylated antibodies may be detected by their interaction with conjugates of streptavidin and the reporter enzymes. The same preparation of conjugated streptavidin reporter enzyme may be used with any number of different biotinylated antibodies making this system a highly flexible one. The reporter molecule may be bound to streptavidin covalently, or biotinylated and attached to streptavidin via the streptavidin-biotin interaction. Since streptavidin is multivalent (binding 4 molecules of biotin per tetrameric protein molecule) it may be used in combination with biotinylated antibody and biotinylated reporter enzymes to obtain amplified signals. Such amplification in ELISA\'s is otherwise difficult to obtain and requires the introduction of additional antibody components. ELISA systems employing streptavidin can readily detect sub-nanogram amounts of antigens. Streptavidin conjugates are widely used together with a conjugate of biotin for specific detection of a variety of proteins, protein motifs, nucleic acids and other molecules since streptavidin has a very high binding affinity for biotin. This RPE-streptavidin conjugate comprises streptavidin (as the biotin-binding protein) with RPE covalently attached (as the fluorescent label). It is commonly used as a second step reagent for indirect immunofluorescent staining, when used in conjunction with biotinylated primary antibodies. It is a very valuable tool for biotin-streptavidin-based biological assays and tests using flow cytometry, microplate reader and microarray platforms.

Citations

View all 17 citations: Citation Explorer
Development of a biotin-streptavidin-amplified nanobody-based ELISA for ochratoxin A in cereal
Authors: Sun, Z., Wang, X., Tang, Z., Chen, Q., Liu, X.
Journal: Ecotoxicol Environ Saf (2019): 382-388
Size effects of magnetic beads in circulating tumour cells magnetic capture based on streptavidin-biotin complexation
Authors: Li, F., Xu, H., Sun, P., Hu, Z., Aguilar, Z. P.
Journal: IET Nanobiotechnol (2019): 6-11
Streptavidin interfacing as a general strategy to localize fluorescent membrane tension probes in cells
Authors: Goujon, A., Strakova, K., Sakai, N., Matile, S.
Journal: Chem Sci (2019): 310-319
Erroneous thyroid and steroid hormones profile due to anti-streptavidin antibodies
Authors: Bayart, J. L., Favresse, J., Melnik, E., Lardinois, B., Fillee, C., Maiter, D., Gruson, P. D.
Journal: Clin Chem Lab Med (2019): se name="16885.enl" path="C:\Website\Referenc
Interference of High Dose Biotin Supplementation with Thyroid Parameters in Immunoassays Utilizing the Interaction between Streptavidin and Biotin: a Case Report and Review of Current Literature
Authors: Mrosewski, I., Neumann, I., Switkowski, R.
Journal: Clin Lab (2019): se name="16885.enl" path="C:\Website\Referenc

References

View all 195 references: Citation Explorer
Overexpression of CXCR2 predicts poor prognosis in patients with colorectal cancer.
Authors: Zhao, Jingkun and Ou, Baochi and Feng, Hao and Wang, Puxiongzhi and Yin, Shuai and Zhu, Congcong and Wang, Shenjie and Chen, Chun and Zheng, Minhua and Zong, Yaping and others, undefined
Journal: Oncotarget (2017)
Cadherin-12 enhances proliferation in colorectal cancer cells and increases progression by promoting EMT
Authors: Ma, Junjun and Zhao, Jingkun and Lu, Jun and Wang, Puxiongzhi and Feng, Hao and Zong, Yaping and Ou, Baochi and Zheng, Minhua and Lu, Aiguo
Journal: Tumor Biology (2016): 1--12
Transplantation of RADA16-BDNF peptide scaffold with human umbilical cord mesenchymal stem cells forced with CXCR4 and activated astrocytes for repair of traumatic brain injury
Authors: Shi, W and Huang, CJ and Xu, XD and Jin, GH and Huang, RQ and Huang, JF and Chen, YN and Ju, SQ and Wang, Y and Shi, YW and others, undefined
Journal: Acta Biomaterialia (2016): 247--261
The migration and differentiation of hUC-MSCsCXCR4/GFP encapsulated in BDNF/chitosan scaffolds for brain tissue engineering
Authors: Huang, Chuanjun and Zhao, Longxiang and Gu, Jun and Nie, Dekang and Chen, Yinan and Zuo, Hao and Huan, Wei and Shi, Jinlong and Chen, Jian and Shi, Wei
Journal: Biomedical Materials (2016): 035004
Antiprothrombin antibodies in a patient with secondary antiphospholipid syndrome and bleeding
Authors: Gonzalez Leon R, Garcia Hern and ez FJ, Castillo Palma MJ, Sanchez Roman J.
Journal: Med Clin (Barc) (2011): 668
Page updated on October 12, 2024

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Physical properties

Solvent

Water

Storage, safety and handling

H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22

Storage

Freeze (< -15 °C); Minimize light exposure
UNSPSC12171501
ELISA Assays with streptavidin conjugates
ELISA Assays with streptavidin conjugates
ELISA Assays with streptavidin conjugates