Production of lactoferricin and other cationic peptides from food grade bovine lactoferrin with various iron saturation levels.
Purification of lactoferricin (Lfcin), a cationic antimicrobial peptide, was achieved by peptic digestion of food grade bovine lactoferrin (LF) followed by fractionation on an industrial grade cation exchange resin with stepwise salt gradient elution. The digest and eluted fractions were partially characterized by MALDI-ToF MS and N-terminal sequencing. A fraction eluted using phosphate buffer with 2.0 M NaCl contained predominantly two peptides with masses of 3196 and 3124 Da, which corresponded to the 26- and 25-amino acid peptides FKCRR WQWRM KKLGA PSITC VRRAF (A), containing the Lfcin sequence. Putative sequences of cationic peptides in other eluted fractions included FKNKS RSFQ, WRMKK LGAPS ITCVR RA, and GAPSI TCVRR AFALE CIRAI AEKKA. The iron saturation level of LF had no effect on the production of Lfcin. Nevertheless, the digestion of LF containing lower iron content led to the production of a higher quantity of low molecular weight cationic peptides. A two-step process using industrial grade cation exchange resin led to 35% recovery of Lfcin and also produced other cationic peptides with potential bioactive properties.
Chan
Judy C K
JC
Food, Nutrition, and Health, Faculty of Land and Food Systems, Room 212, Food, Nutrition and Health Building, The University of British Columbia, 2205 East Mall, Vancouver, British Columbia, Canada.
Li-Chan
Eunice C Y
EC
D000595:Amino Acid Sequence; D000818:Animals; D002412:Cations; D002417:Cattle; D007501:Iron / Q000032:analysis*; D007781:Lactoferrin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010434:Pepsin A / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002412:Cations; D010455:Peptides; C082171:lactoferricin B; D007501:Iron; D007781:Lactoferrin; D010434:Pepsin A