Ki67/MKI67 Protein, Human, Recombinant (GST Tag)

MKI67 contains 1 FHA domain and plays a key role in cell proliferation. During interphase, the MKI67 antigen can be exclusively detected within the cell nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. MKI67 protein is present during all active phases of the cell cycle (G1, S, G2, and mitosis), but is absent from resting cells. MKI67 is an excellent marker to determine the growth fraction of a given cell population. The fraction of MKI67-positive tumor cells is often correlated with the clinical course of cancer. It is also associated with ribosomal RNA transcription. Inactivation of antigen MKI67 leads to inhibition of ribosomal RNA synthesis. The MKI67 protein is a nuclear and nucleolar protein, which is tightly associated with somatic cell proliferation. Antibodies raised against the human MKI67 protein paved the way for the immunohistological assessment of cell proliferation, particularly useful in numerous studies on the prognostic value of cell growth in clinical samples of human neoplasms. MKI67 protein expression is an absolute requirement for progression through the cell-division cycle. Recently, MKI67 is proved to be an independent prognostic factor for disease-free survival (HR 1.5-1.72) in multivariate analyses studies using samples from randomized clinical trials with secondary central analysis of the biomarker. MKI67 was not found to be predictive for long-term follow-up after chemotherapy. Nevertheless, high KI-67 was found to be associated with immediate pathological complete response in the neoadjuvant setting, with an LOE of II-B. MKI67 could be considered as a prognostic biomarker for therapeutic decision.

At Leading Biology, the biological activity of a recombinant protein is routinely measured using a bioassay, e.g. chemotaxis or cell proliferation assay, enzyme assay, or a functional ELISA. When a recombinant protein is an enzyme, specific activity is derived from an enzymatic assay. Each enzyme is tested for potency by cleavage of a substrate. We are in the process of updating the biological activity data. If you have any questions regarding this update, please feel free to contact our technical support team.

Lyophilized from sterile PBS, pH 7.4. Please contact us for any concerns or special requirements. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization. Please refer to the specific buffer information in the hard copy of CoA.

The recombinant human MKI67 /GST chimera consists of 354 amino acids and has a predicted molecular mass of 41 kDa. It migrates as an approximately 37-41 KDa band in SDS-PAGE under reducing conditions.

In general, recombinant proteins are provided as lyophilized powder which are shipped at ambient temperature. Bulk packages of recombinant proteins are provided as frozen liquid. They are shipped out with blue ice unless customers require otherwise. Stable for 1 year at -20°C or below from date of shipment. For maximum recovery of product, centrifuge the original vial after thawing and opening the cap. For long-term storage, aliquot and store at -20°C or below. Avoid repeated freeze-thaw cycles.