Use of 4-D proteomics to differentiate between bovine and camel lactoferrin

Lactoferrin is a multifunctional protein that has various biological activities and applications. However, different sources of lactoferrin may have different properties and characteristics. In this study, we hypothesized that ultra-performance liquid chromatography quadrupole time-of-flight mass spectroscopy (UPLC-QTOF-IMS) coupled with UNIFI software can differentiate bovine lactoferrin from camel lactoferrin based on the unique peptides produced by trypsin digestion. We enzymatically digested the proteins using trypsin and analyzed the resulting peptides using Uniport software and in silico digestion. We identified 14 marker peptides that were unique to bovine lactoferrin and could be used to distinguish it from camel lactoferrin. We also demonstrated the advantages of 4D proteomics over 3D proteomics in separating and identifying peptides based on their mass, retention time, intensity, and ion mobility. This method can be applied to other lactoferrin sources and improve the quality control and authentication of lactoferrin products.