Protein through hydrolysis

In Vitro Enzymatic Modification of Proteins Through Hydrolysis... 

Enzymatic modification of proteins applicable to foods is reviewed by Whitaker ( ). Described briefly are present uses of proteolytic enzymes for modifying proteins through partial hydrolysis. Major emphasis is placed on those enzymes which bring about aggregation of proteins, cross-link formation, and side chain modification through post-translational changes in the polypeptide chain. 

Thus, ATP serves at least three roles in intracellular proteolysis (1) It functions in the tagging of proteins through covalent attachment of ubiquitin, (2) it activates proteases such as La through hydrolysis, and (3) it serves as a positive allosteric effecter of other proteases without being hydrolyzed. The presumed function of this energetic requirement is to ensure the fidelity of protein degradation. It is, after all, nearly as important to cellular function to degrade proteins correctly as it is to synthesize them correctly. 

FhuD delivers the ferric-siderophore complex to the FhuBC complex in the cytoplasmic membrane. FhuB is an intrinsic cytoplasmic membrane protein through which the iron complex can pass, driven by energy supplied by ATP hydrolysis catalyzed by the ATPase FhuC. Ferrous iron may be released from the hydroxamate via reduction by the reductase FhuF, which is loosely associated with the cytoplasmic membrane and, like FhuD, appears to have a lower specificity than FhuA and is active with coprogen and ferrichrome. ... 

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