Jf. Penrose et al., PURIFICATION OF HUMAN LUNG LEUKOTRIENE C-4 SYNTHASE AND PREPARATION OF A POLYCLONAL ANTIBODY, American journal of respiratory and critical care medicine, 152(1), 1995, pp. 283-289
Citations number
31
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
Leukotriene (LT) C-4 synthase is an integral membrane protein that cat
alyzes the conjugation of LTA(4) to reduced glutathione to form LTC(4)
. LTC(4) synthase has been cloned and characterized from transformed c
ell lines, but the protein has not been defined from a tissue source.
LTC(4) synthase was purified to homogeneity from human lung tissue, ut
ilizing S-hexyl glutathione chromatography followed by LTC(4) affinity
chromatography. A greater than 100,000-fold purification with a yield
of 8 to 25% (n = 4) was achieved. The purified LTC(4) synthase migrat
ed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-P
ACE) as an 18-kD protein, and its 19 N-terminal amino acid sequence is
identical to that of purified LTC(4) synthase from KC-1 myeloid cells
or from expression cloning of a KG-1 library in COS cells. Using a ra
bbit polyclonal IgC raised against purified LTC(4) synthase, SDS-PAGE
immunoblotting of LTC(4) synthase from human lung tissue, eosinophils,
KG-1 cells, and platelets showed an 18-kD protein. Immunofluorescence
staining of alveolar macrophages in human lung sections with the anti
-LTC(4) synthase IgG revealed LTC4 synthase to be largely perinuclear
in distribution. Thus, LTC4 synthase, the biosynthetic enzyme responsi
ble for the formation of cysteinyl LTs, is present in lung tissue in a
form apparently identical to that of hematopoietic cells.