Species : |
Streptomyces avidinii |
Source : |
E.coli |
Tag : |
His |
Conjugation/Label : |
N-Cys |
Description : |
Cysteine-streptavidin (Cys-streptavidin) is an engineered streptavidin that contains a cysteine residue at the n-terminus. Cysteine-streptavidin has four identical subunits and binds specifically to biotin with an extremely high affinity. In addition, the unique cysteine residue offers site-specific conjugation. Hence, cysteine-streptavidin can create a conjugate with an optimum molar ratio. Moreover, the cys-streptavidin protein has a C-terminal polyhistidine tag to purify streptavidin and conjugates under mild conditions. |
Form : |
Liquid |
Molecular Mass : |
17.9 kDa (Monomer) |
AA Sequence : |
DPSKDSKAQVSAAEAGITGTWYNQLGSTFIVTAGADGALTGTYESAVGNAESRYVLTGRYDSAPATDGSGTALGWTVAWKNNYRNAHSATTWSGQYVGGAEARINTQWLLTSGTTEANAWKSTLVGHDTFTKVKPSAASIDAAKKAGVNNGNPLDAVQQ |
Biotin binding Site : |
4 |
Dissociation Constant : |
10^-14 mol/L |
Elution : |
Neutral pH (PBS-imidazole) |
Purity : |
≥ 95% by SDS-PAGE |
Applications : |
In vitro research use only
Features
• High affinity for biotin
• High specificity for biotin
• Site-specific conjugation due to the single cysteine
• Mild purification due to the 8 × His tag
Site-specific conjugation of Cysteine-streptavidin (His-tag)
• Enzyme (HRP, phosphatase, beta-galactosidase, luciferase, glucose oxidase)
• Dye (FITC, Cy5, Cy3, Alexa, ATTO, DyLight)
• Fluorescent protein (R-PE, B-PE, APC, PerCP, GFP, RFP)
• Oligonucleotide
• Solid support (agarose, gold particle) |
Storage : |
Short Term Storage: -20 centigrade
Long Term Storage: -20 centigrade
Avoid freeze/thaw cycle. Aliquot upon arrival. |
Storage Buffer : |
20 mM HEPES, 0.5 mM TCEP, pH7.0 |
Concentration : |
> 2.0 mg/mL |
Shipping : |
Cold packs |