Description_x000D_ General description_x000D_ SILu™ Prot IL-6 is a recombinant, stable isotope-labeled human IL-6 which incorporates [13C6, 15N4]-Arginine and [13C6, 15N2]-Lysine. Expressed in human 293 cells, it is designed to be used as an internal standard for bioanalysis of IL-6 in mass-spectrometry. SILu™ Prot IL-6 is a monomer of 183 amino acids, with a molecular weight of ~21 kDa._x000D_ Suggested Quantitative Analysis Parameters_x000D_ (MRM settings provided for three suggested peptides)_x000D_ Biochem/physiol Actions_x000D_ IL-6 is an abundant cytokine, which is crucial for leukocyte and endothelial cell activation. IL-6 is one of the major cytokines that are implicated clinically as biomarkers in ACS (Acute Coronary Syndrome). Its pathophysiological contribution to ACS is the induction of acute-phase response. Patients with ACS have increased circulating levels of IL-6 compared with those patients who have stable angina. Among patients with unstable angina, an increase in IL-6 levels that occurred 48 hours after admission compared with the admission value was associated with the combined end point of death, myocardial infarction (MI), or refractory angina. High levels of IL-6 are also related to cardiovascular disease, heart attack, and stroke._x000D_ Sequence_x000D_ VPPGEDSKDVAAPHRQPLTSSERIDKQIRYILDGISALRKETCNKSNMCESSKEALAENNLNLPKMAEKDGCFQSGFNEETCLVKIITGLLEFEVYLEYLQNRFESSEEQARAVQMSTKVLIQFLQKKAKNLDAITTPDPTTNASLLTKLQAQNQWLQDMTTHLILRSFKEFLQSSLRALRQM_x000D_ Physical form_x000D_ Supplied as a lyophilized powder containing phosphate buffered saline._x000D_ Legal Information_x000D_ This product is licensed under U.S. Patent No. 7,396,688 and foreign counterparts from E. I. du Pont de Nemours and Company. The purchase of this product conveys to the buyer the nontransferable right to use the purchased amount of the product for research and development only, including services for a third party for consideration. The buyer cannot sell or otherwise transfer this product, its components or materials made using this product or its components to a third party. Information about licenses for excluded uses is available from: E. I. du Pont de Nemours and Company; Attn: Associate Director, Commercial Development; DuPont Experimental Station E268; 200 Powdermill Rd.; Wilmington, DE 19803; 1-877-881-9787 (voice), 1-302-695-1437 (fax), licensing@dupont.com._x000D_ SILu is a trademark of Sigma-Aldrich Co. LLC