Department of Physiological Chemistry, University Medical Center Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.|Department of Physiological Chemistry, University Medical Center Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.|Department of Physiological Chemistry, University Medical Center Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.|Department of Physiological Chemistry, University Medical Center Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.|Department of Physiological Chemistry, University Medical Center Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands.