design of specific supramolecular structures (new biomaterials), leading to new
functionalities, constitutes great scientific and technologic challenges in food
science and also in various fields such as in nano- and medical technologies. The
main advantages of the self-assembly approach compared to other ways used for the
production of supramolecular structures (high temperatures, unpleasant chemicals
or solvents, mechanical stresses, etc.) lie in the step-by-step control of polymer
association (bottom-up approach) and a reduction of energy costs [26, 27]. Other
specificities are that protein self-assembly is usually reversible, i.e. that assembly or
disassembly may be triggered by modifications of the physicochemical conditions
of the aqueous solution. In addition, the composition and yield of formation
of supramolecular structures resulting from self-assembly are precise and are
adjustable by slight changes in the physicochemical conditions of the medium
[12, 28].
Literature reviews describing experimental and/or theoretical polymer–polymer
assembly is abundant and diversified regarding the nature of the polymers and
physicochemical conditions used and the supramolecular structures obtained
[29–35]. In this review, we will focus on recent data on food protein assembly.
After a description of the structure and main properties of some important food
proteins, we will describe first the protein-induced assemblies that lead to regular
supramolecular structures and, in a second part the spontaneous protein self-assembly
potential with a special emphasis on systems containing more than one protein.
2 Structure and Properties of Some Food Proteins
In this section, a brief overview of the structural characteristics of the food proteins
most widely used in studies on protein–protein complex formation is presented.
Proteins presented below and in Table 1 are from milk [β-lactoglobulin (β-Lg),
α-lactalbumin (α-La), bovine serum albumin (BSA), lactoferrin, caseins] or egg
white (ovalbumin, lysozyme), even if proteins from other sources (including gelatin
and soy and wheat proteins) are also used for self-assemblies and complex formation studies. The proteins presented are mainly monomers, but are able to selfassemble into oligomers or aggregates in some specific conditions. These
conditions are also addressed.
2.1 General Aspects of Proteins
Proteins are complex natural macromolecules made up of successive amino acids
that are covalently bonded together in a head-to-tail arrangement through amide
bonds. Each protein molecule is composed of an exact sequence of amino acids
determined by the genetic code and arranged in a linear fashion. Proteins are
zwitterions because they contain both positive and negative charges in a proportion
that depends on the amino-acid composition. Hence, proteins are weak
70
S. Bouhallab and T. Croguennec
functionalities, constitutes great scientific and technologic challenges in food
science and also in various fields such as in nano- and medical technologies. The
main advantages of the self-assembly approach compared to other ways used for the
production of supramolecular structures (high temperatures, unpleasant chemicals
or solvents, mechanical stresses, etc.) lie in the step-by-step control of polymer
association (bottom-up approach) and a reduction of energy costs [26, 27]. Other
specificities are that protein self-assembly is usually reversible, i.e. that assembly or
disassembly may be triggered by modifications of the physicochemical conditions
of the aqueous solution. In addition, the composition and yield of formation
of supramolecular structures resulting from self-assembly are precise and are
adjustable by slight changes in the physicochemical conditions of the medium
[12, 28].
Literature reviews describing experimental and/or theoretical polymer–polymer
assembly is abundant and diversified regarding the nature of the polymers and
physicochemical conditions used and the supramolecular structures obtained
[29–35]. In this review, we will focus on recent data on food protein assembly.
After a description of the structure and main properties of some important food
proteins, we will describe first the protein-induced assemblies that lead to regular
supramolecular structures and, in a second part the spontaneous protein self-assembly
potential with a special emphasis on systems containing more than one protein.
2 Structure and Properties of Some Food Proteins
In this section, a brief overview of the structural characteristics of the food proteins
most widely used in studies on protein–protein complex formation is presented.
Proteins presented below and in Table 1 are from milk [β-lactoglobulin (β-Lg),
α-lactalbumin (α-La), bovine serum albumin (BSA), lactoferrin, caseins] or egg
white (ovalbumin, lysozyme), even if proteins from other sources (including gelatin
and soy and wheat proteins) are also used for self-assemblies and complex formation studies. The proteins presented are mainly monomers, but are able to selfassemble into oligomers or aggregates in some specific conditions. These
conditions are also addressed.
2.1 General Aspects of Proteins
Proteins are complex natural macromolecules made up of successive amino acids
that are covalently bonded together in a head-to-tail arrangement through amide
bonds. Each protein molecule is composed of an exact sequence of amino acids
determined by the genetic code and arranged in a linear fashion. Proteins are
zwitterions because they contain both positive and negative charges in a proportion
that depends on the amino-acid composition. Hence, proteins are weak
70
S. Bouhallab and T. Croguennec