The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 21, 2000
Filed:
Nov. 16, 1998
George P Livi, Havertown, PA (US);
Megan M McLaughlin, Drexel Hill, PA (US);
Theodore J Torphy, Bryn Mawr, PA (US);
SmithKline Beecham Corporation, Philadelphia, PA (US);
Abstract
Isolated cDNA clones from human brain (frontal cortex) cDNA libraries that encode a unique subtype of the low K.sub.m, cAMP-specific phosphodiesterases (PDE IVs) are disclosed. Analysis of the distribution of hPDE IV.sub.B mRNA expression in various human tissues using a nonconserved fragment of the cDNA as a probe revealed a restricted pattern of expression, with an .about.4-kb mRNA detected in brain, heart, lung and skeletal muscle and not in placenta, liver, kidney or pancreas. Furthermore, an additional .about.5-kb hPDE IV.sub.B.sup.- related mRNA species was detected in brain tissue. Expression of hPDE IV.sub.B in a genetically-engineered PDE-deficient strain of the yeast Saccharomyces cerevisiae resulted in the overproduction of cAMP PDE activity which displayed the expected kinetic characteristics for a PDE IV: 1) low K.sub.m (4.3 .mu.M) for cAMP, 2) high K.sub.m (>3 mM) for cGMP, and 3) sensitivity to rolipram (K.sub.i =0.085 .mu.M), a selective inhibitor of PDE IV. Recombinant hPDE IV.sub.B also bound [.sup.3 H] R-rolipram saturably and with a high affinity. Analysis of [.sup.3 H] R-rolipram binding data revealed curvilinear Scatchard plots, suggesting the presence of two non-interacting high affinity rolipram binding sites (K.sub.d =0.4 and 6 nM) or a negatively cooperative interaction among multiple binding sites. This novel enzyme is particularly useful for screening candidate compounds for their ability to serve as potential anti-depressant, antiasthmatic or anti-inflammatory agents.