This method results in a significant reduction in deactivation time and a symmetric activation profile. Neither technology prevents shadows, while both produce a distinct sound upon activation and deactivation. It has an SH2 and SH3 domain, which are responsible for its activation and deactivation. Coking is one of several mechanisms for the deactivation of a heterogeneous catalyst. This is a form of enzymatic deactivation. Ozone sterilization is currently being studied as a potential method for prion denaturation and deactivation. Without the deactivation of the catalyst, the alkene produced would be further reduced to alkane. Therefore, it is phosphorylation at site 1 that is responsible for pyruvate dehydrogenase deactivation. Proteolysis is irreversible, which implies the need of a process of enzyme deactivation. Highway mileage was improved from to with the addition of Active Fuel Management cylinder deactivation. P, leading to adenylylation and subsequent deactivation of GS. Several automotive manufacturers have engines with cylinder deactivation in current production. The Hemi V8 also comes with a "fuel-saver" (cylinder deactivation) mode. In 2005 Fiat introduced a version of the 16v incorporating port deactivation (PDA) and EGR. It is used as a metal deactivation additive in fuels.