Isolation of recombinant proteins from milk

Area of Science:

• Biochemistry
• Biotechnology
• Food Science

Background:

• Milk is a complex biological fluid containing fat globules and casein micelles, posing challenges for protein purification.
• Recombinant protein production in milk offers high yields but requires specialized isolation techniques.
• Proteases present in milk can degrade target recombinant proteins, necessitating careful processing.

Purpose of the Study:

• To outline the challenges and strategies for purifying recombinant proteins produced in milk.
• To discuss the behavior of milk components (fat, casein) during purification.
• To highlight the advantages of high-yield recombinant protein production in milk.

Main Methods:

• Centrifugation to remove fat globules.
• Precipitation of casein micelles using low pH or chemical agents.
• Solubilization of associated proteins with chelating agents if necessary.
• Standard separation techniques applied to clarified milk.

Main Results:

• Casein micelles and fat globules act as separate phases, hindering filtration and standard separation.
• Recombinant proteins may associate with casein micelles, requiring specific solubilization steps.
• Effective separation is achievable after removing or disrupting casein micelles and fat.

Conclusions:

• Milk's complex composition requires specific pre-processing steps for recombinant protein isolation.
• Leveraging the association of recombinant proteins with milk components can aid purification.
• High concentrations of recombinant proteins in milk are a significant advantage, simplifying purification despite inherent challenges.