SIRT 1, Recombinant, Human (Sirtuin 1, Sir2-related Protein Type 1, Sir2-like 1, Silent Mating Type

Human Sirtuin 1 (GenBank Accession No. NM_012238), amino acids 193-741 with N-terminal GST tag, expressed in E. coli expression system. The gene hSIR2 (SIRT1), the human homolog of the S. cerevisiae Sir2 protein known to be involved in cell aging and in the response to DNA damage. Despite its conservation in organisms from bacteria to human and its general requirement for transcriptional silencing in yeast, the function of the Sir 2 protein is unknown. Sir 2, a conserved protein required for silencing in yeast, has recently been found to couple histone deacetylation to cleavage of a high-energy bond in nicotinamide adenine dinucleotide (NAD) and the synthesis of a novel product, O-acetyl- ADP-ribose. In vitro studies have shown Sir 2 to be able to transfer labeled phosphate from NAD to itself and histones. The unusual coupling of deacetylation to cleavage and synthesis of other bonds raises the possibility that deacetylation is not the only crucial function of Sir 2. The unprecedented coupling of amide bond cleavage to cleavage of a high-energy bond raises the possibility that NAD breakdown by Sir 2 plays an important role in silencing that is independent of its requirement for deacetylation. The ADP-ribosyltransferase activity of Sir 2 has been found to be essential for its silencing function. Yeast Sir 2 is a heterochromatin component that silences transcription at the silent mating loci, telomeres and the ribosomal DNA, and also suppresses recombination in the rDNA and extends replicative life span. Specific Activity: ~10 pmol/min/ug , Assay Condition: , 50mM Tris/HCl, pH 8.0, 137mM sodium chloride, 2.7mM KCl, 1mM MgCl2, 0.05% Tween-20, 20uM HDAC substrate, 500uM NAD+ and 20ng/ul Sirtuin 1. Incubation Condition: 30 min at 37ºC. Applications: Useful for the study of enzyme kinetics, screening inhibitors and selectivity profiling. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: For long-term storage, aliquot to avoid repeated freezing and thawing and freeze at -70°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for 6 months.