A metabolon is a temporary structural-functional complex formed between sequential enzymes of a metabolic pathway, held together by noncovalent interactions, and structural elements of the cell such as integral membrane proteins and proteins of the cytoskeleton.

The concept of structural-metabolic cellular complexes was first conceived in 1970 by A. M. Kuzin of the USSR Academy of Sciences, and adopted in 1972 by P. A. Srere of the University of Texas for the enzymes of the Tricarboxilic Acids (Szent Györgyi-Krebs) Cycle. This hypothesis was well accepted in the former USSR and further developed for the complex of glycolytic enzymes (Embden-Meyerhof-Parnas Pathway) by B.I. Kurganov and A.E. Lyubarev. In the middle 70’s the group of F.M. Clarke at the University of Queensland, Australia also worked on the concept . The name “METABOLON” was first proposed in 1985 by P. Srere during a lecture in Debrecen, Hungary.

The formation of metabolons allows passing (channelling)

Substrate channeling

Substrate channeling is when the intermediary metabolic product of one enzyme is passed directly to another enzyme or active site without being released into solution. When several consecutive enzymes of a metabolic pathway channel substrates between themselves, this is called a metabolon...

the intermediary metabolic product from an enzyme directly as substrate into the active site of the consecutive enzyme of the metabolic pathway. The Kreb's Cycle (Tricarboxylic Acid Cycle, Citric Acid Cycle) is an example of a metabolon which facilitates substrate channeling. During the functioning of metabolons the amount of water needed to hydrate the enzymes is reduced and the enzyme activity is increased.

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!colspan=6 style="background:#000000;color:#fff;"|Metabolic pathways in which occuurs formation of metabolons
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!width=180px;|Metabolic pathway
!width=140px;|Events supporting metabolon's formation
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|DNA biosynthesis||A, B, C, E, F
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|RNA biosynthesis|| A, B, C, E, F
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|Protein biosynthesis||A, B, C, D, E
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|Glycogen biosynthesis||C, E
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|Pyrimidine biosynthesis||A, C, D, F
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|Purine biosynthesis||A,E
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|Lipid biosynthesis||A,B,C,H
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|Steroid biosynthesis||A,C,E
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|Metabolism of amino acids||A,B,D,H
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|Glycolysis||A,B,C,D,I
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|Tricarboxilic acids cycle||B,C,D,E,G
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|Fatty acids oxidation||A,B,C,D
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|Electron transport||C,I
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|Antiobiotic biosynthesis||A,E
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|Urea cycle||B,D
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|cAMP Degradation||A,D,E
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!colspan=4| A - Channeling, B - Specific protein-protein interactions, C - Specific protein - membrane interactions, D - Kinetic effects, E - Multienzyme complexes identified, F - Genetic proofs, G - Operative modeled systems, H - Identified multifunctional proteins, I - Physico-chemical proofs.
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