Determination of Lactoferrin in Camel Milk by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry Using an Isotope-Labeled Winged Peptide as Internal Standard.

Xia Li,Ling Chen,Lu Chen,Dongliang Guo,Hua Feng,Enmin Xu,Ligang Deng,Zengmei Li

doi:10.3390/molecules24224199

Abstract

An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of lactoferrin in camel milk based on the signature peptide. The camel lactoferrin was purified by heparin affinity chromatography and then used to screen tryptic signature peptides. The signature peptide was selected on the basis of sequence database search and identified from the tryptic hydrolysates of purified camel lactoferrin by ultrahigh-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry. The pretreatment procedures included the addition of isotope-labeled winged peptide and the disposal of lipids and caseins followed by an enzymatic digestion with trypsin. Analytes were separated on an Acquity UPLC BEH 300 C18 column and then detected on a triple-quadrupole mass spectrometer in 7 min. The limits of detection and quantification were 3.8 mg kg−1 and 11 mg kg−1, respectively. The recoveries ranged from 74.5% to 103.6%, with relative standard deviations below 7.7%. The validated method was applied to determine the lactoferrin in ten samples collected from Xinjiang Province.

Highlights

Lactoferrin is an iron-binding glycoprotein that was first identified in 1939 in bovine milk [1], and in 1960 it was isolated from human milk by Johannson [2]
All of the results demonstrated that the current method had good recovery and precision, and that it was able to satisfy the requirements for the quantification of camel lactoferrin in camel milk
We developed and validated a UHPLC-mass spectrometer (MS)/MS method for the quantitative determination of camel lactoferrin on the basis of the signature peptide derived from the tryptic hydrolysates of camel lactoferrin

Summary

Introduction

Lactoferrin is an iron-binding glycoprotein that was first identified in 1939 in bovine milk [1], and in 1960 it was isolated from human milk by Johannson [2]. It belongs to the family of transferrins, together with serum transferrin, ovotransferrin, and melanotransferrin [3]. Molecules 2019, 24, 4199 diseases [10,11]. These factors make it a supplementary functional food and stimulate increasing interest in exploiting the therapeutic value of lactoferrin [8,12]

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Conclusion