Protein

Cap Z, Capping protein (non-muscle isoform)

Origin

recombinant, human recombinant

Molecular mass

66kDa

Protein description

The subunits of the heterodimeric capping protein CapZ possess a molecular mass of 34kDa (alpha 1-subunit) and 32kDa (beta 2-subunit, His-tagged). CapZ binds with high affinity in a Ca⁺⁺-independent manner to the barbed end of actin filaments (1:1000 M/M).

Actin interaction

Ca⁺⁺-insensitive barbed end capping protein. Kd actin binding = >1nM (barbed end) .

Form

Lyophilized, ready-to-use.

Quantity per unit

1.0 mg

Buffer

150mM NaCl, 20mM Hepes pH 7.4, 1mM DTT and 5% sucrose, when reconstituted with 1.0ml ultrapure water to obtain a 1.0 mg/ml solution.

Purity & Activity

Purity: >94% by scanning densitometry from Coomassie G-250 stained SDS-Gels.

Capping activity: F-actin (Cat.#:8101) containing 20% pyrene actin (Cat.#: 8112) was incubated with CapZ and diluted below the critical concentration. Depolymerisation was followed by fluorometry and compared to an actin reference without CapZ.

Complete capping was obtained at a molar ratio of 1 : 1000 (CapZ : Actin). All proteins were used as supplied, i.e. without dialysis. G-Actin stock solutions were pre-spun 1h, 100.000xg, 4°C.  

Purification notes

The alpha-1 SU is untagged, while the beta-2 SU contains a His-tag. Using anti-His antibodies, the protein can be identified by all suited immunological  techniques.

Protein concentration

Determined by OD280 (0.1%=1.234).

Storage instructions

CapZ is stored at –70°C upon arrival will be stable in performance for at least 6 months from the date of purchase. The solubilized protein is kept on ice and should be stored at -20°C in glycerol or CryoProtect (Cat.#: 6011-01). Avoid repeated freeze / thaw cycles. 

Shipping conditions 

At ambient temperature. Upon delivery store at -70°C.

Remarks

For Use in Research only. Not for Use in Human or Veterinary Diagnostical or Therapeutical Applications.

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