Protein Complexes as Biochemically 

 Active Systems 



G. A. DEBORIN 

 A. N. Bakh Institute of Biochemistry, U.S.S.R. Academy of Sciences, Moscow 



Science to-day is in possession of certain information about the possible paths 

 of evolution of matter from inorganic compounds resulting in the appearance 

 of organic substances, amino acids, polypeptides, etc. The least-studied stage 

 in the development of matter towards the appearance of Ufe seems to be the 

 transition from relatively simple protein-like substances to biochemical systems 

 of ever increasing complexity and then to complex protein systems displaying 

 metabohsm [i]. 



The data accumulated by biochemistry indicate that, owing to their high 

 reactivity, proteins do not, as a rule, occur in contemporary hving organisms in 

 the free state, but are to be foimd in them in various complex formations with 

 one another and with other substances. This appears to be one of the causes of 

 what is known as the microheterogeneity of proteins. It is also characteristic 

 that most enzymes are compounds of proteins with non-protein substances, 

 which are largely responsible for the specificity and activity of enzymes. 



These facts suggest that the first phase in the appearance of multimolecular 

 protein systems might have been the formation of complexes of varying degrees 

 of complexity, the components of which might have been primordial proteins 

 and various groups of non-protein substances that, compounded with a 

 corresponding protein, become capable of diverse transformations. The forma- 

 tion of such complexes may have been one of the stages in the appearance of 

 conjugated proteins, including enzymes. In the process of their subsequent 

 evolution these compounds acquired the specific functions in which they funda- 

 mentally differ from their constituents. 



In connection with these concepts it appears highly interesting to elucidate 

 the mechanism of formation and biochemical peculiarities of protein complexes, 

 since the data obtained in this way would enable us to gain an insight into certain 

 chemical processes underlying biological phenomena. 



The information available concerning the interaction of proteins with other 

 proteins [2] nucleic acids [3], polysaccharides [4], lipids [5], detergents [6], ions 

 [7] etc., indicates that, depending on the chemical nature of the reactants, the 

 character of the bonds arising between them may differ. Evidence is on hand 

 pointing to the fact that the links between the components of such complexes 

 may be based either on electrostatic interactions, or hydrogen bonds, or van der 

 Waals' forces, or, finally, on covalent chemical bonds. It is natural to expect 



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