Some regulatory properties of purine nucleoside phosphorylase of <i>Bacillus cereus</i>

Serra, María; Falcone, Giuseppe

doi:10.1016/0014-5793(71)80480-5

FEBS Letters

1971

DOI: 10.1016/0014-5793(71)80480-5

|View full text |Cite

Some regulatory properties of purine nucleoside phosphorylase of Bacillus cereus

María Serra

Giuseppe Falcone

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1978

2003

Publication Types

Select...

Article3

Relationship

Self Cite0

Independent3

Authors

Journals

Cited by 3 publications

(1 citation statement)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ribonucleoside hydrolases catalyze the hydrolytic cleavage of ribonucleosides into their respective bases and free pentose. Most of the reports concerning the enzymatic mechanisms of the catabolism of nucleosides were developed largely through studies on mammalian tissues (MOHAMUD et al 1990), bacteria (LAMPEN and WANG 1952, TAKAGI and HORECKER 1957, TERADA et al 1967, SERRA et al 1971, RADER and HOCHSTADT 1976, yeast (CARTER 1950, HEPPEL and HILMOE 1952, MAGNI et al 1974). In the literature few studies on purine ribonucleoside cleavage by extracts of filamentous fungi were reported.…”

mentioning

confidence: 99%

Hydrolytic cleavage of purine ribonucleosides in Aspergillus phoenicis

Abdel‐Fatah

Elsayed²,

Elshafei

2003

J. Basic Microbiol.

View full text Add to dashboard Cite

Cell-free extracts of nitrate-grown Aspergillus phoenicis could catalyze the hydrolytic cleavage of the N-glycosidic bond of inosine, guanosine and adenosine to the corresponding base and ribose by the nucleoside hydrolase. No evidence was obtained concerning the hydrolytic degradation of N-glycosidic bond of pyrimidine ribonucleosides namely cytidine and uridine by the same extracts. Optimum pH and temperature for adenosine, guanosine and inosine hydrolysis were the same at pH 3.5 and 55 degrees C, respectively. Citrate buffer showed the highest hydrolase activity when compared to the analogous activity obtained with the other buffers used. The rate of hydrolysis of the three nucleosides was in the order inosine > guanosine > adenosine. Incubation of extracts at 55 degrees C for 15 minutes caused about 85%, 75% and 62% loss of activity with adenosine, guanosine and inosine respectively. Dialyzing the extract caused a decrease in enzyme activity. Addition of inorganic arsenate to the reaction mixture (containing adenosine, guanosine or inosine) did not affect the amount of ribose liberated. Addition of EDTA at a concentration of 5 x 10(-3) M caused an inhibition of about 50%, however a complete inhibition for enzyme activity was obtained at 10(-2) M EDTA. MgSO4, CoSO4 and ZnSO4 at a final concentration of 5 x 10(-3) M showed activation of ribonucleoside hydrolase.

show abstract

mentioning

confidence: 99%

Hydrolytic cleavage of purine ribonucleosides in Aspergillus phoenicis

Abdel‐Fatah

Elsayed²,

Elshafei

2003

J. Basic Microbiol.

View full text Add to dashboard Cite

show abstract

Inosine nucleosidase from Azotobacter vinelandii

1978

View full text Add to dashboard Cite

An enzyme catalyzing the hydrolysis of purine nucleosides was found to occur in the extract of Azotobacter vinelandii, strain O, and was highly purified by ammonium sulfate fractionation, DEAE-cellulose chromatography, hydroxylapatite chromatography and gel filtration on Sephadex G-150. A strict substrate specificity of the purified enzyme was shown with respect to the base components. The enzyme specifically attacked the nucleosides without amino groups in the purine moiety: inosine gave the maximum rate of hydrolysis and xanthosine was hydrolyzed to a lesser extent. The pH optimum of inosine hydrolysis was observed from pH 7 to 9, while xanthosine was hydrolyzed maximally at pH 7. The Km values of the enzyme for inosine were 0.65 and 0.85 mM at pH 7.1 and 9.0, respectively, and the value for xanthosine was 1.2 mM at pH 7.1. Several nucleotides inhibited the enzyme: the phosphate portions of the nucleotides were suggested to be responsible for the inhibition by nucleotides. Although the inhibition of the enzyme by nucleotides was apparently non-competitive type with respect to inosine, allosteric (cooperative) binding of the substrate was suggested in the presence of the inhibitor. The physiological significance of the enzyme was discussed in connection with the degradation and salvage pathways of purine nucleotides.

show abstract

Mode and extent of degradation of adenosine and guanosine by extracts of Aspergillus terricola

Elshafei

Abu-Shady

El-Beih

et al. 1995

Microbiological Research

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Some regulatory properties of purine nucleoside phosphorylase of Bacillus cereus

Cited by 3 publications

References 16 publications

Hydrolytic cleavage of purine ribonucleosides in Aspergillus phoenicis

Hydrolytic cleavage of purine ribonucleosides in Aspergillus phoenicis

Inosine nucleosidase from Azotobacter vinelandii

Mode and extent of degradation of adenosine and guanosine by extracts of Aspergillus terricola

Contact Info

Product

Resources

About