Determinants of pH profile and acyl chain selectivity in lysosomal phospholipase A₂.

ABSTRACT: Lysosomal phospholipase A2 (LPLA₂) is characterized by broad substrate recognition, peak activity at acidic pH, and the transacylation of lipophilic alcohols, especially N-acetyl-sphingosine. Prior structural analysis of LPLA₂ revealed the presence of an atypical acidic residue, Asp13, in the otherwise hydrophobic active site cleft. We hypothesized that Asp13 contributed to the pH profile and/or substrate preference of LPLA₂ for unsaturated acyl chains. To test this hypothesis, we substituted Asp13 for alanine, cysteine, or phenylalanine; then, we monitored the formation of 1-O-acyl-N-acetylsphingosine to measure the hydrolysis of sn-1 versus sn-2 acyl groups on a variety of glycerophospholipids. Substitutions with Asp13 y

SUBMITTER: Hinkovska-Galcheva V 

PROVIDER: S-EPMC6027918 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature