Individual and combined action of pancreatic lipase and pancreatic lipase‐related proteins 1 and 2 on native versus homogenized milk fat globules

Abstract

Pancreatic lipase (PL) and pancreatic lipase-related proteins 1 and 2 (PLRP1 and PLRP2) display different functional properties, despite close structures. The aim of the study was to compare the kinetic properties of recombinant human PLRP1, PLRP2, and PL on a physiological substrate: the milk fat under native and homogenized structures. No lipolytic activity is measured for PLRP1. PLRP2 hydrolyses milk fat with a lower catalytic efficiency than that of PL. PLRP2 activity, higher on homogenized than on native milk fat, is differently influenced by fatty acids (FA) and colipase depending on a proteolytic cleavage in the lid domain. FA enhance the activity on both milks. A colipase positive effect on the non-proteolyzed PLRP2 is observed on homogenized milk and with FA on native milk fat. Bile salts are necessary. An original observation is a synergic effect between PL and PLRP2 on the two milks. An inhibitory effect of PLRP1 on PL activity is also demonstrated. The combined action of pancreatic lipases on milk fat digestion proposes PLRPs as modulators of PL. Our study supports the hypothesis of a major role of PLRP2 in fat digestion in newborns and brings new insights to understand the physiological role of PLRPs.

BSSL and PLRP2: key enzymes for lipid digestion in the newborn examined using the Caco-2 cell line

“…A similar synergistic effect was recently shown for PLRP2 and PTL when digesting TG presented as bovine milk fat globules ( 33 ) and for PTL and PLRP2 when digesting RE ( 29 ). The molecular or physical-chemical explanation behind these synergisms are presently not understood; however, a synergistic effect between PLRP2 and BSSL should be important in neonatal lipid digestion as the capacity to digest fat is often a limiting factor in energy utilization, particularly when it is from infant formula or pasteurized human milk, as neither contains active BSSL ( 18 ).…”

Biophysical Aspects of Lipid Digestion in Human Breast Milk and Similac™ Infant Formulas

“…Similarly, Berton et al reported a similar lag phase for hydrolysis of triglycerides in raw, non-homogenised cow's milk by human pancreatic lipase [61]. Structurally, breast milk fat globules differ from those of infant formula.…”

Emerging Approaches for the Treatment of Fat Malabsorption Due to Exocrine Pancreatic Insufficiency

“…Phospholipids Galactolipids Esters of vitamin A Berton & al., 2009Thirstrup & al., 1994Sias & al., 2004Reboul & al., 2006 Carboxyl ester lipase Verheij & al., 1983 Abbreviations: HPL, human pancreatic lipase; TG, triglycerides Table 2. Human pancreatic enzymes involved in lipid digestion…”

“…The pancreatic lipase-related 2 protein (hPLRP2), with a broader substrate specificity, hydrolyzes milk triglycerides (Berton & al., 2009) phospholipids (Jayne & al., 2002;Lowe, 2002;Thirstrup & al., 1994) galactolipids (Sias & al., 2004) and esters of lipid-soluble vitamins (Reboul & al., 2006). Carboxyl ester lipase (also called bile salt-stimulated lipase, On a weight basis, the ratio of pancreatic lipase to gastric lipase total secretory outputs was found to be around four after 3 hours of digestion.…”