Studies on sulphatases. 20. Enzymic cleavage of aryl hydrogen sulphates in the presence of H218O

Spencer, B.

doi:10.1042/bj0690155

Cited by 68 publications

(28 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our findings are also supported by earlier studies, where Spencer (1957), Cloves et al (1977), and recently Bao and Kohl (2006) found no evidence of an isotope exchange between APS and ambient water.…”

Section: Oxygen Isotope Exchangesupporting

confidence: 93%

Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

Mangalo

Stichler

Einsiedl

2007

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Section: Oxygen Isotope Exchangesupporting

confidence: 93%

Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

Mangalo

Stichler

Einsiedl

2007

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…However, both monoalkyl (13) and monoaryl (14) sulfates have been shown to undergo C-O cleavage in alkali, and Fig. 3 shows that the OH Ϫ ion falls on the same line as other nucleophiles.…”

Section: Discussionmentioning

confidence: 92%

Monoalkyl sulfates as alkylating agents in water, alkylsulfatase rate enhancements, and the “energy-rich” nature of sulfate half-esters

Wolfenden

Yuan²

2007

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Alkyl sulfate monoesters are involved in cell signaling and structure. Alkyl sulfates are also present in many commercial detergents. Here, we show that monomethyl sulfate acts as an efficient alkylating agent in water, reacting spontaneously with oxygen nucleophiles >100-fold more rapidly than do alkylsulfonium ions, the usual methyl donors in living organisms. These reactions of methyl sulfate, which are much more rapid than its hydrolysis, are insensitive to the nature of the attacking nucleophile, with a Brønsted ␤nuc value of ؊0.01. Experiments at elevated temperatures indicate a rate constant of 2 ؋ 10 ؊11 s ؊1 for the uncatalyzed hydrolysis of methyl sulfate at 25°C (t 1/2 ‫؍‬ 1,100 y), corresponding to a rate enhancement of Ϸ10 11 -fold by a human alkylsulfatase. Equilibria of formation of methyl sulfate from methanol and sodium hydrogen sulfate indicate a group transfer potential (⌬G pH7) of ؊8.9 kcal/mol for sulfate ester hydrolysis. The magnitude of that value, involving release of the strong acid HSO 4 ؊ , helps to explain the need for harnessing the free energy of hydrolysis of two ATP molecules in activating sulfate for the biosynthesis of sulfate monoesters. The ''energy-rich'' nature of monoalkyl sulfate esters, coupled with their marked resistance to hydrolysis, renders them capable of acting as sulfating or alkylating agents under relatively mild conditions. These findings raise the possibility that, under appropriate circumstances, alkyl groups may undergo transfer from alkyl sulfate monoesters to biological target molecules.group transfer potential ͉ methyl transfer ͉ sulfate monoester D imethyl sulfate and other diesters of sulfuric acid are powerful alkylating agents, widely used in organic synthesis and chemically induced mutagenesis. Monoalkyl sulfates, in contrast, undergo spontaneous hydrolysis only at high temperatures (1) and appear never to have been shown to act as alkylating agents under any conditions. Many commercial detergents, formulated on the basis of that presumed lack of reactivity, incorporate SDS, also known as sodium lauryl sulfate, as their active ingredient. In living organisms, O-sulfated lipids and polysaccharides, produced through the intermediacy of 3Ј-phosphoadenosine 5Ј-phosphosulfate, are involved in maintaining cell structure. Sulfate monoesters also play a central role in recently discovered signaling functions that are sensitive to variations in their detailed structures (for recent reviews, see refs. 2 and 3).The identification of roles for sulfuric acid monoesters in biological signaling and structure has aroused increasing interest in the chemical properties of these negatively charged molecules, and of the enzymes responsible for their biosynthesis and degradation. To appreciate the effectiveness of any enzyme as a catalyst, it is of interest to compare the rate of an enzyme reaction with the rate of a reaction proceeding in water in the absence of a catalyst. Recent work has shown that hydrolases that act on phosphate monoesters produce rate enhancements...

show abstract

“…With the symmetrical esters the question of inversion of configuration does not arise, but presumably here, too, C-O cleavage occurs. This mechanism is proving to be a common feature of both primary (Cloves et al, 1977) and secondary (Bartholomew et al, 1977) alkylsulphohydrolases in the detergent-degrading bacteria, Pseudomonas C 12B and C. terrigena, and contrasts sharply with the arylsulphohydrolases where, in all cases examined, S-0 cleavage is the rule (Spencer, 1958(Spencer, , 1959Cloves et al, 1977). Such divergence in behaviour must surely arise from fundamental differences in the mechanism of action of the two types of sulphohydrolase, although what these differences may be must, for the time, remain a mystery.…”

Section: Molecular-weight Determinationsmentioning

confidence: 99%

Substrate specificity and other properties of the inducible S3 secondary alkylsulphohydrolase purified from the detergent-degrading bacterium Pseudomonas C12B

Shaw¹,

Dodgson²,

White³

1980

Biochemical Journal

View full text Add to dashboard Cite

The inducible S3 secondary alkylsulphohydrolase of the soil bacterium Pseudomonas C 12B was purified to homogeneity (683-fold from cell-free extracts by a combination of column chromatography on DEAE-cellulose, Sephadex G-100 and Blue Sepharose CL-6B. The enzyme has a molecular weight in the region of 40000-46 000, and is active over a broad range of pH from 5 to 9, with maximum activity at pH 8.2. The preferred substrates of the enzyme are the symmetrical secondary alkylsulphate esters such as heptan-4-yl sulphate and nonan-5-yl sulphate and the asymmetric secondary octyl and nonyl sulphate esters with the sulphate group attached to C-3 or C-4. However, for each asymmetric ester, the L-isomer is much more readily hydrolysed than the D-isomer. This specificity is interpreted in terms of a three-point attachment of the substrate to the enzyme's active site. The alkyl chains on either side of the esterified carbon atom are bound in two separate sites, one of which can only accommodate alkyl chains of limited size. The third site binds the sulphate group. Enzymic hydrolysis of this group is accompanied by complete inversion of configuration at the asymmetric carbon atom. The implied cleavage of the C-O bond of the C-O-S ester linkage was confirmed by 180-incorporation studies.

show abstract

Studies on sulphatases. 20. Enzymic cleavage of aryl hydrogen sulphates in the presence of H218O

Cited by 68 publications

References 14 publications

Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

Monoalkyl sulfates as alkylating agents in water, alkylsulfatase rate enhancements, and the “energy-rich” nature of sulfate half-esters

Substrate specificity and other properties of the inducible S3 secondary alkylsulphohydrolase purified from the detergent-degrading bacterium Pseudomonas C12B

Contact Info

Product

Resources

About