title: Pancreatic lipase-related protein 2 digests fats in human milk and formula in concert with gastric lipase and carboxyl ester lipase.
abstract: BACKGROUND
  Dietary fats must be digested into fatty acids and monoacylglycerols prior to absorption. In adults, colipase-dependent pancreatic triglyceride lipase (PTL) contributes significantly to fat digestion. In newborn rodents and humans, the pancreas expresses low levels of PTL. In rodents, a homologue of PTL, pancreatic lipase-related protein 2 (PLRP2), and carboxyl ester lipase (CEL) compensate for the lack of PTL. In human newborns, the role of PLRP2 in dietary fat digestion is unclear. To clarify the potential of human PLRP2 to influence dietary fat digestion in newborns, we determined PLRP2 activity against human milk and infant formula.
  
  
  METHODS
  The activity of purified recombinant PLRP2, gastric lipase (GL), and CEL against fats in human milk and formula was measured with each lipase alone and in combination with a standard pH-stat assay.
  
  
  RESULTS
  Colipase added to human milk stimulated fat digestion. PLRP2 and CEL had activity against human milk and formula. Predigestion with GL increased PLRP2 activity against both substrates. Together, CEL and PLRP2 activity was additive with formula and synergistic with human milk.
  
  
  CONCLUSIONS
  PLRP2 can digest fats in human milk and formula. PLRP2 acts in concert with CEL and GL to digest fats in human milk in vitro.
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh at University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: Karin
authors.initials: K
authors.lastname: Johnson
authors.forename: Leah
authors.initials: L
authors.lastname: Ross
authors.forename: Rita
authors.initials: R
authors.lastname: Miller
authors.forename: Xunjun
authors.initials: X
authors.lastname: Xiao
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lowe
mesh_terms: D000704:Analysis of Variance; D003089:Colipases / Q000302:isolation & purification / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D041943:Infant Formula / Q000378:metabolism*; D007231:Infant, Newborn; D008049:Lipase / Q000302:isolation & purification / Q000378:metabolism*; D008895:Milk, Human / Q000378:metabolism*; D010843:Pichia
chemical_list: D003089:Colipases; D008049:Lipase; C054621:CEL protein, human; C485982:LIPF protein, human; C075988:pancreatic lipase related protein 2