Latency-Associated Peptide of Transforming Growth Factor beta 1 (LAP TGF-b1)
LAP TGF-b1 assay detects human LAP TGF-b1 and Latent TGF-b1, but not active/free TGF- b1, The assay is a good surrogate biomarker for free TGF-b1. Measuring the total amount of free TGF-b1 requires acidification and neutralization of samples to release free TGF-b1 from LAP and LTBP. Free TGF-b1 is transient, does not circulate and is meant to act locally (autocrine and paracrine factor) upon activation of LAP TGF-b1. Latency Associated Peptide (LAP) is derived from the N-terminal region of the TGF-b1 propeptide and is bound to TGF-b1 to form a complex called Small Latent Complex (SLC). This complex remains in the cell until it is bound by another protein called Latent TGF-?-Binding Protein (LTBP), forming a larger complex called Large Latent Complex (LLC) that can be secreted. TGF-b1 is a multifunctional regulatory cytokine and growth factor controlling cell division, development, homeostasis, apoptosis, and the immune system.
Swiss-Prot Accession Number: P01137