DMSP-lyase

Ansede JH, PJ Pellechia, DC Yoch (2001) Ansede JH, PJ Pellechia, DC Yoch (2001) Nuclear magnetic resonance analysis of [l- C]dimethylsulfoniopropionate (DMSP) and [l- C]acrylate metabolism by a DMSP lyase-producing marine isolate of the a-subclass proteobacteria. Appl Environ Microbiol 67 3134-3139. 

A dynamic defense model that seems to be widespread among marine algae involves the cleavage of (3-dimethylsufoniopropionate (DMSP) (21) by the enzyme DMSP-lyase resulting in dimethylsulfide (DMS) (22) and acrylate (23) (Scheme 6). 

In addition to their role in chemical defense, DMSP-lyase products may also function as chemical cue in more complex trophic cascades. In the natural environment DMS-production is related to zooplankton herbivory [60] and can thus act as an indicator for the availability of food for planktivorous birds. Indeed, some Antarctic Procellariiform seabirds can detect DMS (22) and are highly attracted to the cue, as was shown with DMS-scented oil slicks on the ocean surface [61]. The odors released during zooplankton grazing (DMS) as well as those of zooplankton itself (e.g., trimethylamine and pyrazines) are attractive to birds [62], thus assisting vertebrate search behavior. 

In simple terms, the global sulfur cycle has two components. One is biochemical involving the conversion of sulfate to sulfide and the formation of DMS the other is atmospheric photochemical oxidation of DMS to sulfur oxyacids. DMS is formed mainly in the oceans by microorganisms and to a lesser extent in plants. About 38M0 Tg year-1 of DMS are released to the atmosphere from the oceans. The major precursor for DMS formation is the sulfonium salt, dimethylsulfoniopropionate, (CH3)2 S+ CH2 CH2 COOH, DMSP. DMSP lyase enzymes catalyze an elimination of acrylic acid from DMSP (Equation 12) with the release of DMS ... 

DMSP lyase activity has been shown to be present in one of the most common ulvoid algae in the region, Ulva lactuca, a species that contains relatively high amounts of DMSP (Van Alstyne et al. 2001b). 

Stefels J, Dijkhuizen L (1996) Characteristics of DMSP-lyase in Phaeocystis sp. (Prymnesio-phyceae). Mar Ecol Prog Ser 131 307-313... 

Steinke M, Daniel C, Kirst GO (1996) DMSP lyase in marine macro- and microalgae intraspe-cific differences in cleavage activity. In Kiene RP, Visscher P, Keller M, Kirst GO (eds) Biological and environmental chemistry of DMSP and related sulfonium compounds. Plenum, New York, pp 317-323... 

Steinke M, Wolfe GV, Kirst GO (1998) Partial characterisation of dimethylsulfoniopropionate (DMSP) lyase isozymes in 6 strains of Emiliania huxleyi. Mar Ecol Prog Ser 175 215-225... 

Induction of chemokinetic ability also occurs in Alcaligenes strain M3A.60 Dimethyl sulfonio-propionate (DMSP) is an attractant for bacteria that have been induced to produce DMSP lyase. Such cells are attracted to DMSP at ecologically relevant concentrations, but uninduced cells do not respond to DMSP. Since DMSP lyase produces dimethylsulfide, which is important to global climate regulation, Zimmer-Faust et al.60 suggest that bacterial chemokinesis may play a critical role in global sulfur cycles and climate. 

Maintenance of intracellular DMSP concentration algal DMSP-lyase activity... 

Algae can adjust the intracellular concentration of DMSP through the biosynthetic (anabolic) or the degradation (catabolic) pathways. DMSP-lyase enzymes facilitate the degradation pathway, in which DMSP is cleaved to DMS, acrylate and a proton. What controls the activity of DMSP-lyases in phytoplankton is still unknown. Stefels (2000) suggested... 

ItS Table 3 Kinetic parameters of DMSP-lyase in whole-cell samples (in vivo activity) and in crude extracts (in vitro activity) of cultures or field samples. Data are usually... 

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