Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Leukotriene (LT) C4 synthase catalyzes the conjugation of LTA4 with reduced glutathione (GSH) to form LTC4, the parent compound of cysteinyl leukotrienes. It is a 18 kDa protein that functions as homodimer. Cloning of LTC4 synthase cDNA reveals amino acid homology with 5-lipoxygenase activating protein (FLAP) and newly identified microsomal glutathione S-transferase II (mGST-II) but not with cytosolic GSTs or mGST-I. LTC4 synthase gene contains 5 exons and four introns. This gene has been localized to the long arm of human chromosome 5 at the region of 5q35 which is in close proximity to the cluster of genes that are involved in inflammation and asthma. Mutagenic studies reveals that amino acid residues Arg-51 and Tyr-93 are critical for catalytic function. Arg-51 was proposed to open the epoxide ring of LTA4 and Tyr-93 to provide the thiolate anion of GSH.