Table 4.
Structure/Function Analysis of Several ASM Mutations
| Residue | Structure/Function Implications |
| G21X | Reveals that first in-frame ATG is functional |
| C92W | May affect disulfide bond formation; within saposin domain (conserved aa with saposins A–D) |
| C157R | May affect disulfide bond formation; within saposin domain (conserved aa with saposins A–D) |
| R376H and R376L | Within putative sphingomyelin binding domaina |
| H421Y | Within zinc binding domain; within putative active site regionb |
| C431R | May affect disulfide bond formation |
a
Putative sphingomyelin binding domain based on homology to the sphingomyelin binding protein, lysenin.
b
Putative active site region based on homologies to phospholipases C and A2.