GD (-) Aachen, a new variant of deficient glucose-6-phosphate dehydrogenase

✍ Scribed by Axel Kahn; Albrecht Esters; Manfred Habedank

• Publisher: Springer
• Year: 1976
• Tongue: English
• Weight: 804 KB
• Volume: 32
• Category: Article
• ISSN: 0340-6717
• DOI: 10.1007/bf00291500

✦ Synopsis

A deficient G-6PD variant was discovered in 4 males of one family from northwestern Germany. Five generations of this family could be studied. The deficient G-6PD was a new variant, called "Gd (--) Aachen". Its main characteristics are the following: severe enzyme deficiency in erythrocytes (3% of normal), contrasting with an almost normal activity in leukocytes; normal molecular specific activity (i.e., normal ratio enzyme activity/cross-reacting material); slow mobility in starch gel electrophoresis (92-94% of normal); increased Michaelis constant for glucoes-6-phosphate (60-70 muM) and NADP+ (20-25 muM); decreased inhibition constant by NADPH with respect to NADP+ (7 muM); increased inhibition by ATP; normal utilization of the substrate analogues; slightly biphasic pH curve; thermal instability, and normal activation energy of the enzymatic reaction. The relationships between the hematologic disorders (severe and frequent hemolytic crises) and the unfavorable kinetic modifications are discussed.