Differential expression of corticostatins/defensins: higher levels of CS-4 (NP-2) transcripts compared with CS-6 (NP-5) in rabbit lung.

cDNA clones encoding two members of the corticostatin (CS)/defensin family of peptides have been isolated from a rabbit bone marrow cDNA library through cross-hybridization with cDNA encoding the human corticostatin HP-4. They encode the precursors of CS-4 (NP-2, MCP-2) and CS-6 (NP-5). Highly specific probes were generated for Northern blotting of RNA from various normal rabbit tissues.

The gene encoding the human corticostatin HP-4 precursor contains a recent 86-base duplication and is located on chromosome 8.

The human neutrophil-derived cationic peptide HP-4 exhibits corticostatic activity on adrenal cells and is an L-type calcium channel agonist at nanomolar concentrations. Complementary DNA clones encoding the HP-4 precursor have been isolated from a human bone marrow cDNA library by screening with oligonucleotide probes. The nucleotide sequence shares about 72% identity with the cDNA encoding defensin HP-1, but differs from it, and from other genes of this family characterized to date, by an extra 83-base segment.

Agarose gel patterns of alkaline phosphatase isoenzymes before and after treatment with neuraminidase.

The clinical value of alkaline phosphatase isoenzyme analysis is limited by the inability of most electrophoretic methods to resolve the liver and bone isoenzymes. The authors attacked this problem by treating serum samples with neuraminidase, then running treated and untreated samples side-by-side on specially prepared agarose gels. Each isoenzyme showed a characteristic mobility before and after neuraminidase treatment that allowed its identification.