Premium
Purification and characterization of leukotriene A 4 hydrolase from human epidermis
Author(s) -
Iversen Lars,
Kristensen Peter,
Nissen Judith B.,
Merrick William C.,
Kragballe Knud
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)01459-e
Subject(s) - leukotriene b4 , hydrolase , leukotriene , chemistry , biochemistry , keratinocyte , epidermis (zoology) , microbiology and biotechnology , enzyme , biology , in vitro , immunology , inflammation , anatomy , asthma
The leukotriene A 4 hydrolase is a central enzyme in leukotriene B 4 , formation. Unlike 5‐lipoxygenase, leukotriene A 4 hydrolase activity is present in normal human epidermis, where it is likely to be involved in transcellular leukotriene formation. In this study the leukotriene A 4 hydrolase was purified from human epidermis and human cultured keratinocytes and compared with leukotriene A 4 hydrolase from human neutrophils. To purify leukotriene A 4 hydrolase from human epidermis a new non‐specific affinity chromatography column, with the leukotriene A 4 hydrolase inhibitor bestatin coupled to AH‐Sepharose, was introduced. The epidermal leukotriene A 4 hydrolase was purified to apparent homogeneity and the molecular weight was determined to be approximately 70,000 Da by SDS‐PAGE. The pI was 5.1–5.4 for the epidermal as well as the keratinocyte and neutrophil leukotriene A 4 hydrolase, as determined by chromatofocusing. Only minor differences in the amino acid composition were seen between the three enzyme sources. The optimal pH for the hydrolase activity was 7.5–8.5 for the epidermal and neutrophil leukotriene A 4 hydrolases. Finally, it was also shown that the epidermal leukotriene A 4 hydrolase undergoes suicide inactivation when transforming leukotriene A 4 into leukotriene B 4 . It was concluded that there is a close resemblance between the epidermal leukotriene A 4 , hydrolase and the hydrolase found in other cell types. Therefore, the human epidermis may be a good model for the in vivo study of transcellular leukotriene formation.