Here are a couple of reasons that enzymes could become inactive in solution. Most of this depends on the concept that an enzyme is a large polypeptide chain with a tertiary structure that is relatively unstable compared to simple chemical catalysts. Changes in this structure can lead to its inactivation.:
1. Denaturation of the enzymes by agitation at air:water interfaces. Do you see soap-like bubbles when you shake the enzyme solution? Uh oh, that is enzyme that has lost its tertiary structure by denaturation caused by separation of hydrophilic and hydrophobic regions of the polypeptide chains at the air:water interface. Better be careful mixing this solution and use swirling, rather than shaking motions. Hint: roll it between your palms.
2. Degradation due to proteases. The world (inc. probably record surfaces) is full of proteases made by microbes and even your fingers and these can attack enzymes and inactivage them by cleaving the polypeptide chain into smaller pieces and amino acids.
3. Inactivation due to inhibition. Enzymes often require cofactors to work and depletion of these can inhibit further enzyme action. Alternatively, inhibitor molecules can bind to the enzyme and modify it to an inactive state.
Hope this helps clarify things. (I am a molecular biologist with a background in protein x-ray crystallography and the design of peptide detergents.)
1. Denaturation of the enzymes by agitation at air:water interfaces. Do you see soap-like bubbles when you shake the enzyme solution? Uh oh, that is enzyme that has lost its tertiary structure by denaturation caused by separation of hydrophilic and hydrophobic regions of the polypeptide chains at the air:water interface. Better be careful mixing this solution and use swirling, rather than shaking motions. Hint: roll it between your palms.
2. Degradation due to proteases. The world (inc. probably record surfaces) is full of proteases made by microbes and even your fingers and these can attack enzymes and inactivage them by cleaving the polypeptide chain into smaller pieces and amino acids.
3. Inactivation due to inhibition. Enzymes often require cofactors to work and depletion of these can inhibit further enzyme action. Alternatively, inhibitor molecules can bind to the enzyme and modify it to an inactive state.
Hope this helps clarify things. (I am a molecular biologist with a background in protein x-ray crystallography and the design of peptide detergents.)