Characterization and chromosomal localization of ELANH2, the gene encoding human monocyte/neutrophil elastase inhibitor.

Human monocyte/neutrophil elastase inhibitor (HEI) is a protease inhibitor of the serpin superfamily that rapidly inactivates neutrophil elastase, proteinase-3, and possibly cathepsin-G in vitro and, by regulating these potent proteases, is thought to prevent tissue damage at inflammatory sites. The HEI gene (ELANH2) was characterized by amplifying intron regions using cDNA-specific primers. Intron positions of ELANH2 were found to be homologous to intron positions in the genes for the serpin molecules chicken ovalbumin and human plasminogen activator inhibitor-2 (PLANH2). Because serpin superfamily genes in general have widely different organizational patterns, the shared organization of these genes strengthens the evidence that they form a subgroup or family, the "ovalbumin-related serpin" ("Ov-serpin") family. By amplifying DNA of a somatic cell hybrid panel, ELANH2 was unambiguously localized to chromosome 6. The use of a panel of radiation and somatic cell hybrids specific for chromosome 6 refined the localization of ELANH2 to the short arm telomeric of D6S89, F13A, and D6S202 at 6p24-pter. Another Ov-serpin gene PI6 (placental thrombin inhibitor) was colocalized to the same region, thus defining an Ov-serpin locus on chromosome 6 in addition to the previously defined PLANH2-containing Ov-serpin locus on chromosome 18.