Sphingomyelinase activities in cultured skin fibroblasts from patients with Niemann-Pick disease

✍ Scribed by Ryoji Minami; Yoshiki Matsuura; Fukumi Nakamura; Tooru Kudoh; Hideaki Sogawa; Kazuhiko Oyanagi; Kazuko Sukegawa; Tadao Orii; Kootaroo Maruyama; Tooru Nakao

• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 469 KB
• Volume: 47
• Category: Article
• ISSN: 0340-6717
• DOI: 10.1007/bf00273198

✦ Synopsis

Sphingomyelinase activity in cultured skin fibroblasts from a fetus affected with infantile-type Niemann-Pick disease was 0.5% of control activity; the activities in cells from two patients with adult-type disease (Cases 2 and 3) were 5.0% and 59.0%. Sphingomyelinase activiy was separated into three peaks (I-III) by isoelectric focusing. The isoelectric points were 4.5, 4.9, and 5.2 for peaks I, II, and III, respectively. The three peaks in the Case 2 cells were drastically reduced; only a very small peak could be distinguished (pI of 4.7). On the other hand, three peaks were observed in the Case 3 cells. Peak I had a pI of 4.4, peak II a pI of 4.7, and peak III a pI of 5.2. Peak I was found at near normal level, but both peaks II and III were markedly reduced. Sphingomyelinase in the peak I fraction obtained from isoelectric focusing in Case 3 cells was found to have the same Km value as that in control cells.