Alkyl sulfatases

Although sulfate is formed by hydrolysis of both alkyl and aryl sulfates, the pathway of degradation for aryl sulfates is controlled by the source of sulfur (Cook et al. 1999). The complex issues surrounding the hydrolysis of sulfate esters have been discussed (Kertesz 1999), and are illustrated by the number and substrate specificity of alkyl sulfatases for the surfactant 2-butyloctyl sulfate in Pseudomonas sp. strain AE-A (Ellis et al. 2002). 

Gadler, P. and Faber, K., New enzymes for biotransformations microbial alkyl sulfatases displaying stereo- and enantioselectivity. Trends Biotechnol., 2007, 25, 83. 

Wallner, S.R., Bauer, M., Wiirdemann, C., Wecker, P., Gloeckner, F.O. and Faber, K., Flighly enantioselective rec-alkyl sulfatase activity of the marine planctomycete Rhodopirellula baltica shows retention of configuration. Angew. Chem. Int. Ed., 2005, 44, 6381. 

Pogorevc, M. and Faber, K., Enantioselective stereoinversion of rec-alkyl sulfates by an alkyl-sulfatase from Rhodococcus ruber DSM 44541. Tetrahedron Asymm., 2002,13, 1435. 

The possible persistence in the environment of alkylethoxy sulfates has led to extensive investigations of their degradability. Although the role of alkyl sulfatase activity is noted in Section 6.11.1, ether-cleavage has been shown to be the major pathway for the degradation of dodecyltriethoxy sulfate (Hales et al. 1986). 

Alkyl sulfatases have been found in several lower eukaryotes and prokaryotes, and exhibit no sequence similarity with ASs. The alkyl sulfatases do not have an FGly residue, but bear in the active site a dinuclear Zn " " center, and their sequences are related to those of the metallo-/ -lactamase (MBL) superfamily (Figure 21). Depending on the enzyme and catalytic mechanism the alkyl sulfatases can either cleave the... 

An unusual sulfatase mechanism is observed for alkyl sulfatases from the nonheme Fe, a-ketoglutarate-dependent dioxygenase superfamilyThese enzymes cleave a variety of sulfate esters by a complex radical mechanism, yielding the corresponding aldehyde and inorganic sulfate. The crystal structure of AtsK from Pseudomonas putida, a member of this group of enzymes, has been solved and a mechanism proposed... 

To the best of our knowledge, the O-sulfonate modification of serine and threonine is so far not found in nature, but the existence of alkyl-sulfatases has been considered to support its occurrence [199]. 

This would be analogous to the change that results from alkyl substitution that is, transition states become more associative in the continuum from monoesters to triesters. Although relatively few phosphatases have been subjected to serious scrutiny of their transition states, in the cases that have been reported, this prediction has not been borne out. The reactions catalyzed by AP proceeds through loose transition states that are not significantly altered from those in solution, both in its phosphatase and in its promiscuous sulfatase activities. " Results with A-phosphatase and with calcineurin, which both catalyze phosphoryl transfer to a metal-coordinated hydroxide nucleophile, also provide no evidence of a significantly different transition state. Protein tyrosine phosphatases (PTPs), which do not contain metal ion cofactors but have a conserved arginine residue and proceed via a phosphocysteine intermediate, similarly catalyze phosphoryl transfer via a transition state similar to the one in solution. ... 

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