Comprehensive review of PDE4 cAMP phosphodiesterase family: structure, regulation, compartmentalization. Does NOT contain primary kinetic measurements — no original Km or Vmax values. The “Houslay 2010” PMID cited in earlier h05 scripts never existed; this 2003 review is the closest Houslay lab primary review. For actual Km measurement use Owens et al. 1997 Biochem J (PMID 9337850): Km = 4.8 µM for full-length PDE4A in COS cells.
Key finding
Review synthesizes PDE4 isoform structure and regulation. Indicates PDE4 Km range for cAMP is ~1–6 µM across isoforms (from primary papers cited within). The h05 model uses PDE4_KM_NM = 4000 nM (4 µM), which falls within the published range. “Houslay 2010” (cited in early h05 scripts) does not exist — no Houslay primary paper from 2010 on PDE4 kinetics has been found.
Numbers that matter
| Parameter | Value | Units | Source within review | Notes |
|---|---|---|---|---|
| PDE4 Km for cAMP | 1–6 | µM | Cited primary papers | Range across isoforms |
| PDE4A Km (primary measurement) | 4.8 | µM | Owens 1997 PMID 9337850 | Full-length PDE4A in COS cells |
| PDE4 Vmax | NOT REPORTED here | — | — | Use primary papers |
| PDE4_KM_NM (h05 model) | 4000 | nM (4 µM) | — | Within published range |
Limitations
- Review paper: no original kinetic measurements.
- “Houslay 2010” citation in prior h05 scripts has no PMID and does not correspond to any confirmed publication.
- For primary measurement use Owens et al. 1997 PMID 9337850 (Km = 4.8 µM, Km_core = 3.3 µM, PDE4A).
Connections
[source]calcium-oscillation — closest Houslay lab reference; replaces phantom “Houslay 2010”[applies]STRC Calcium Oscillation Acoustic Therapy