title: Strategies for the release of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in an enzymatic hydrolyzate of α-lactalbumin.
abstract: Bovine α-lactalbumin (α-La) contains numerous dipeptidyl peptidase IV (DPP-IV) inhibitory peptide sequences within its primary structure. In silico analysis indicated that the targeted hydrolysis of α-La with elastase should release DPP-IV inhibitory peptides. An α-La isolate was hydrolysed with elastase under different conditions using an experimental design approach incorporating 3 factors (temperature, pH and enzyme to substrate ratio (E : S) ratio) at 2 levels. The hydrolyzate generated at pH 8.5, 50 °C, E : S 2.0% (w/w) (H9) displayed the highest mean DPP-IV inhibition value at 3.1 mg mL(-1) of 75.8 ± 3.7% and had a half maximal DPP-IV inhibitory concentration (IC50) value of 1.20 ± 0.12 mg mL(-1). Five α-La-derived DPP-IV inhibitory peptides (GY, GL, GI, NY and WL) predicted to be released in silico were identified by liquid-chromatography tandem mass spectrometry (LC-MS/MS) within H9 and its simulated gastrointestinal digestion (SGID) sample. This preliminary study demonstrated the benefit of using a targeted approach combined with an experimental design in the generation of dietary protein hydrolyzates with DPP-IV inhibitory properties.
authors.affiliation: Proteins and Peptides Research Group, Life Sciences Department, University of Limerick, Limerick, Ireland. dick.fitzgerald@ul.ie.
authors.forename: Alice B
authors.initials: AB
authors.lastname: Nongonierma
authors.forename: Solène
authors.initials: S
authors.lastname: Le Maux
authors.forename: Joël
authors.initials: J
authors.lastname: Hamayon
authors.forename: Richard J
authors.initials: RJ
authors.lastname: FitzGerald
mesh_terms: D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002853:Chromatography, Liquid; D018819:Dipeptidyl Peptidase 4 / Q000737:chemistry; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D007768:Lactalbumin / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D013696:Temperature
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D008894:Milk Proteins; D007768:Lactalbumin; D018819:Dipeptidyl Peptidase 4