LIPF

LIPF Full Name

lipase, gastric

LIPF Introduction

LIPF encodes gastric lipase, also called human gastric lipase (HGL), a member of the conserved acid lipase gene family that also includes lysosomal acid lipase (LIPA) and hepatic lipase (LIPC). The enzyme is synthesized and secreted by the chief cells of the fundic mucosa, the acid-secreting region of the stomach, and it operates under the harsh, low-pH conditions where most other lipases would be inactive. Gastric lipase is unusual among digestive enzymes in that it does not require bile salts or colipase for activity and is remarkably resistant to the proteolytic environment of the stomach. Rather than fully breaking down dietary fat, it performs the first, rate-limiting sn-3 hydrolysis of medium- and long-chain triglycerides, liberating free fatty acids and partial glycerides that prime the lipid emulsion for the more complete digestion that pancreatic lipase will accomplish later in the duodenum.

Although the pancreas contributes the bulk of triglyceride hydrolysis overall, gastric lipase is far from redundant; in humans it accounts for roughly 30 percent of total fat digestion, a share that rises substantially in infants, whose pancreatic lipase is still immature, and in individuals with pancreatic insufficiency. The enzyme's structure reveals how it tolerates acid: a flexible lid domain covers the active site, and a short N-terminal tetrapeptide is indispensable for both lipid binding and catalytic activity. Studies in recombinant and site-directed mutagenized forms have mapped the salt-bridge residues that stabilize this lid and explain the enzyme's strict pH dependence and its preference for medium-chain over long-chain substrates. Beyond digestion, altered LIPF expression has been observed in gastric cancer, where reduced levels correlate with poorer outcomes, suggesting the lipase may also serve as a tissue biomarker. Collectively, LIPF illustrates how a single acid-stable enzyme extends the digestive window upward into the stomach, ensuring efficient extraction of energy from dietary fats from the first moments of a meal.

Alternate Names for LIPF

LIPF; lipase, gastric; gastric triacylglycerol lipase; HGL; HLAL; gastric lipase; GL; MGC138477; MGC142271;

• 1. Pafumi Y, et al. Mechanisms of inhibition of triacylglycerol hydrolysis by human gastric lipase. J Biol Chem. 2002 Aug 2;277(31):28070-9.
  2. Bodmer MW, et al. Molecular cloning of a human gastric lipase and expression of the enzyme in yeast. Biochim Biophys Acta. 1987 Aug 25;909(3):237-44.