Human Epidermal Growth Factor EGF Skin Care Recombinant Core Streptavidin for Cosmetic Materials

Product Name: Recombinant Core Streptavidin (r-cSA)

Formulation: Lyophilized from 5 mM PB (4 mM Na₂HPO₄, 1 mM NaH₂PO₄, pH7.4)

Mol. Wt.: 13.5 kDa for monomer, 54 kDa for tetramer

Theoretical pI: 6.04

Theoretical Activity:

18.1 U/mg protein (r-cSA:Biotin=1:4 (mol:mol))

Activity: ≥16 U/mg protein (Determined by NUPTEC according to modified Green Method)

Resources: Escherichia coli (E. coli)

Purity: ≥95% by SDS-PAGE analysis

Endotoxin: ≤5 EU/mg

Storage Condition: -20 ^oC

Storage Duration: 3 years

Description:

Streptavidin is a homotetrameric protein secreted from Streptomyces avidinii. Similar to avidin, one mole of streptavidin can bind 4 moles of biotin with a high affinity. Streptavidin lacks carbohydrate side chains present on avidin and has an isoelectric point close to neutrality. Therefore it has a reducing nonspecific binding level as compared to avidin. Streptavidin has been extensively applied in various biological fields, such as ELISA, IHC, TRFIA, quantifying PCR, isolation of single-stranded nucleotide, purification of biomolecule, and monoclonal antibody production as well.

Compared to native streptavidin, r-cSA is improved in stability and solubility by the removal of activity-unrelated sequence. Also, one cysteine residue is inserted at the C-terminus of r-cSA for covalently conjugating to resin.