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What is the typical effect of enzyme immobilization on the kinetic parameters of an enzyme's activity?

Can one assume that they'd stay approximately the same or is there a gross change? Any way to estimate the effect?

The native parameters are as follows:

kcat    0.5 1/min
Km      0.6 microM
[E0]    5   micro M
[S]     60  micro M

Could I expect to retain them after immobilization? Or are these too high for an immobilized enzyme?

If it matters, it is a 500 residue enzyme with a MW of approx. 65,000 Da

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The main factor influencing the kinetics of immobilized enzymes is thought to be the rate of diffusion of substrate and product towards and away from the enzyme, respectively.

This has been discussed on ResearchGate and an article in Process Biochemistry from one of those in the discussion quotes figures for effects on immobilized laccase: approx. 100x increase in Km and 2–5x reduction in Vmax (as noted in the poster’s comment).

There are several theoretical treatments of the question:

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  • $\begingroup$ Thanks! Those are great links. What I'd have loved to find was a study of the sort where someone had taken a bunch of enzymes, immobilized them and reported on the change in activities. $\endgroup$ – curious_cat Mar 26 '16 at 2:41
  • $\begingroup$ This snippet from your link is sort of what I wanted: "As expected, after an immobilization process, the apparent Km and Vmax values are significantly affected. In literature, for example, the Vmax value for immobilized laccase compared to that of the free enzyme is reduced of about 2–5 times compared to the free enzyme, due to substrate diffusion to the catalytic site, with an increase of Km value. The increase of Km can be explained as a result of diffusional limitation of the substrate or to conformational changes of the enzyme resulting in a lower affinity of the substrate for the enzyme" $\endgroup$ – curious_cat Mar 26 '16 at 2:45
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    $\begingroup$ Glad the links were of use. I'll flesh out my answer on the basis of your comment to improve it. $\endgroup$ – David Mar 26 '16 at 8:10
  • $\begingroup$ Did you get a chance to flesh out your answer? Any tips would help a lot! $\endgroup$ – curious_cat Apr 2 '16 at 15:23
  • $\begingroup$ Sorry, just the reference. Been busy as was preparing to leave for a week. Currently en route to the French Alps. $\endgroup$ – David Apr 2 '16 at 19:32

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