Nanostructure-Assisted Laser Desorption/Ionization (NALDI) for Analysis of Peptides in Milk and Colostrum
¹Department of Agricultural Products, Estonian Research Institute of Agriculture,Teaduse 13, EE75501 Saku, Estonia; e-mail: email@example.com; firstname.lastname@example.org
²Department of Food Processing, Faculty of Chemical and Materials Technology,Tallinn University of Technology, Estonia
³ Department of Food Science, Aarhus University, Blichers Allé 20, Postboks 50D K-8830 Tjele, Denmark; e-mail: Jan.Stagsted@agrsci.dk
Several bioactive proteins have been identified in colostrum and milk. However there are needs for development of technologies to identify and purify low molecular weight (LMW) peptides with bioactivity. The most used method is Matrix Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS), but matrix suppression often prevents detection of LMW components. Our approach was to work out a suitable method for analysing small peptides in bovine milk and colostrum without extensive sample pre-treatment. Nanostructure-Assisted Laser Desorption/Ionization (NALDI) is a matrix-free method to identify such LMW components. We also made a comparison between MALDI and NALDI for detection of peptides from colostrum samples. Our results show that NALDI provides better intensity compared with MALDI. It allows us to sequence small peptides and to identify a fragment of β-casein from the colostrum sample. Further studies are needed for comprehensive identification and characterization of LMW bioactive peptides from colostrum and milk.