Two New Reactions of the Activated Sulfates Adenylylsulfate and 3′-Phosphoadenylylsulfate with Ammonia

Cooper, Bryan P.; Baumgarten, Franziska E.; Schmidt, Ahlert

doi:10.1515/znc-1980-1-231

Cited by 5 publications

(2 citation statements)

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“…This procedure repeatedly produced ADP due to hydrolysis, and a significant amount (10-20%) of a decomposition product with elution characteristics markedly different from those of ADPS03 on a Mono-Q anion-exchange resin (RT = 4.9 min). On the basis of similar studies with the synthesis of adenosine 5'phosphosulfate (Cooper et al, 1979), this product is tentatively identified as the ß-phosphoramidate of ADP resulting from the reaction of ADPS03 with ammonia: The rate constants were found to be kH+ = 0.15 s-1 M'1 and k0 = 7 X -7 s'1. Kinase Inhibition by ADPSOy ADPSOj was found to be a competitive inhibitor against ATP for the enzymatic reac-figure 1: pH-rate profile for the first-order hydrolysis of ADPS03 at 50 °C, ionic strength 0.1.…”

Section: Resultsmentioning

confidence: 90%

Sulfuryl transfer catalyzed by phosphokinases

Peliska

O’Leary²

1991

Biochemistry

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Adenosine 5'-sulfatopyrophosphate is a substrate for nucleoside diphosphate kinase. The reaction appears to proceed through a ping-pong mechanism analogous to the physiological reaction involving ATP, presumably by way of a sulfohistidine intermediate. Unlike the phosphoryl transfer reactions, the corresponding sulfuryl transfers catalyzed by nucleoside diphosphate kinase do not have a strict divalent metal requirement. The estimated rate constants for the metal- and nonmetal-catalyzed sulfuryl transfers differ by less than an order of magnitude and are approximately 1000-fold slower than the corresponding phosphate transfers. These results suggest that the role of the metal ion in nucleoside diphosphate kinase is to coordinate the alpha, beta-phosphates of the substrate. Sulfuryl and phosphoryl transfer probably occur through dissociative transition states.

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Section: Resultsmentioning

confidence: 90%

Sulfuryl transfer catalyzed by phosphokinases

Peliska

O’Leary²

1991

Biochemistry

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“…Prolonged storage (2 years at -180C) of the ammonium salt of adenosine 5'-phosphosulphate also results in the formation of detectable amounts of adenosine 5'-phosphoramidate. Other workers have found that storage of adenosine 5'-phosphosulphate or adenosine 3'-phosphate 5'-phosphosulphate in the presence of NH4HCO3 yields the corresponding phosphoramidates (Cooper & Triiper, 1979;Cooper et al, 1980).…”

Section: Oriain (mentioning

confidence: 99%

Purification and properties of adenylyl sulphate:ammonia adenylyltransferase from Chlorella catalysing the formation of adenosine 5′-phosphoramidate from adenosine 5′-phosphosulphate and ammonia

Fankhauser

Schiff

Garber

1981

Biochemical Journal

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Extracts of Chlorella pyrenoidosa, Euglena gracilis var. bacillaris, spinach, barley, Dictyostelium discoideum and Escherichia coli form an unknown compound enzymically from adenosine 5'-phosphosulphate in the presence of ammonia. This unknown compound shares the following properties with adenosine 5'-phosphoramidate: molar proportions of constituent parts (1 adenine:1 ribose:1 phosphate:1 ammonia released at low pH), co-electrophoresis in all buffers tested including borate, formation of AMP at low pH through release of ammonia, mass and i.r. spectra and conversion into 5'-AMP by phosphodiesterase. This unknown compound therefore appears to be identical with adenosine 5'-phosphoramidate. The enzyme that catalyses the formation of adenosine 5'-phosphoramidate from ammonia and adenosine 5'-phosphosulphate was purified 1800-fold (to homogeneity) from Chlorella by using (NH(4))(2)SO(4) precipitation and DEAE-cellulose, Sephadex and Reactive Blue 2-agarose chromatography. The purified enzyme shows one band of protein, coincident with activity, at a position corresponding to 60000-65000 molecular weight, on polyacrylamide-gel electrophoresis, and yields three subunits on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of 26000, 21000 and 17000 molecular weight, consistent with a molecular weight of 64000 for the native enzyme. Isoelectrofocusing yields one band of pI4.2. The pH optimum of the enzyme-catalysed reaction is 8.8. ATP, ADP or adenosine 3'-phosphate 5'-phosphosulphate will not replace adenosine 5'-phosphosulphate, and the apparent K(m) for the last-mentioned compound is 0.82mm. The apparent K(m) for ammonia (assuming NH(3) to be the active species) is about 10mm. A large variety of primary, secondary and tertiary amines or amides will not replace ammonia. One mol.prop. of adenosine 5'-phosphosulphate reacts with 1 mol.prop. of ammonia to yield 1 mol.prop. each of adenosine 5'-phosphoramidate and sulphate; no AMP is found. The highly purified enzyme does not catalyse any of the known reactions of adenosine 5'-phosphosulphate, including those catalysed by ATP sulphurylase, adenosine 5'-phosphosulphate kinase, adenosine 5'-phosphosulphate sulphotransferase or ADP sulphurylase. Adenosine 5'-phosphoramidate is found in old samples of the ammonium salt of adenosine 5'-phosphosulphate and can be formed non-enzymically if adenosine 5'-phosphosulphate and ammonia are boiled. In the non-enzymic reaction both adenosine 5'-phosphoramidate and AMP are formed. Thus the enzyme forms adenosine 5'-phosphoramidate by selectively speeding up an already favoured reaction.

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Sulfate activation in Rhodobacter sulfidophilus and other species of the Rhodospirillaceae

Cooper

Trüper

1985

Arch. Microbiol.

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Two New Reactions of the Activated Sulfates Adenylylsulfate and 3′-Phosphoadenylylsulfate with Ammonia

Cited by 5 publications

References 0 publications

Sulfuryl transfer catalyzed by phosphokinases

Sulfuryl transfer catalyzed by phosphokinases

Purification and properties of adenylyl sulphate:ammonia adenylyltransferase from Chlorella catalysing the formation of adenosine 5′-phosphoramidate from adenosine 5′-phosphosulphate and ammonia

Sulfate activation in Rhodobacter sulfidophilus and other species of the Rhodospirillaceae

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