[1] Univ Gottingen, Inst Biochem & Mol Zellbiol, D-37073 Gottingen, Germany
[2] Univ Illinois, Dept Med, Chicago, IL 60612 USA
[3] Univ Illinois, Dept Physiol & Biophys, Chicago, IL 60612 USA
[4] Vet Affair Chicago Healthcare Syst, Chicago, IL 60612 USA