Purification of peptides from colostrum

Abstract

The invention relates to the purification of peptides from colostrum. The method involves the addition of an alcohol such as methanol or ethanol to the mixture in order to form an alcohol phase rich in the peptides, and a precipitate. The peptide-rich alcohol phase is subsequently recovered and subjected to further fractionation. The invention is particularly useful in the purification of colostrinin from colostrum.

1 . A method for recovering peptides from mammalian colostrum, or a derivative of colostrum, said method comprising: mixing the colostrum with an alcohol to form an alcohol phase and a precipitate, the alcohol phase including the alcohol and at least some of the peptides to be recovered; separating the alcohol phase from the precipitate; and recovering the alcohol phase.  
     
     
         2 . The method according to  claim 1 , wherein the alcohol is methanol or ethanol.  
     
     
         3 . The method according to  claim 1 , further comprising the step of removing at least some of the alcohol from the recovered alcohol phase to leave a concentrated peptide phase, and recovering the concentrated peptide phase.  
     
     
         4 . The method according to  claim 3 , further comprising dissolving a precipitation agent in either the recovered alcohol phase or in the concentrated peptide phase, said precipitation agent being capable of inducing precipitation of at least some of the peptides.  
     
     
         5 . The method according to  claim 4 , wherein the precipitation agent is ammonium sulfate.  
     
     
         6 . The method according to  claim 1 , further comprising adding EDTA to the colostrum prior to adding the alcohol.  
     
     
         7 . The method according to  claim 1 , wherein the mixture contains protein micelles to which the peptides are bound, said method further comprising the step of adding a micelle-breaking material to the fluid, prior to the addition of the alcohol, the micelle-breaking material being capable of inducing break up of the micelles in the fluid.  
     
     
         8 . The method according to  claim 7 , wherein the micelle-breaking material is EDTA or EGTA.  
     
     
         9 . The method according to  claim 1 , further comprising adding CaCl 2  to the mixture prior to adding the alcohol.  
     
     
         10 . The method according to  claim 7 , further comprising adding a micelle-restoring material to the fluid, prior to adding the alcohol, in order to re-form the protein micelles.  
     
     
         11 . The method according to  claim 10 , wherein the micelle-restoring material is CaCl 2 .  
     
     
         12 . The method according to  claim 1 , wherein the fluid is preconditioned to a pH in the range 6.5-7.5 before adding the alcohol.  
     
     
         13 . The method according to  claim 1 , wherein the alcohol added to the fluid is an amount sufficient to produce an alcohol concentration, based on the total volume of fluid, of from 40-80% (v/v).  
     
     
         14 . The method according to  claim 1 , wherein the alcohol added to the fluid is an amount sufficient to produce an alcohol concentration, based on the total volume of fluid, of from 50-70% (v/v).  
     
     
         15 . The method according to  claim 1 , wherein the alcohol added to the fluid is an amount sufficient to produce an alcohol concentration, based on the total volume of fluid, of from 55-65% (v/v).  
     
     
         16 . The method according to  claim 1 , wherein the alcohol added to the colostrum is substantially 100% pure.  
     
     
         17 . The method according to  claim 1 , wherein the peptides recovered from the colostrum comprise colostrinin.  
     
     
         18 . The method according to  claim 1 , wherein the fluid is a derivative of mammalian colostrum which has been subjected to one or more treatment steps.