A tie-in between oxalate and arabinose

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Listmates,

Arabinose is a signalling molecule for bacteria like e. coli, but it may be

formed from hyaluronic acid in conditions of inflammation.

In consideration of the relationships described in the articles I've put

below, we may need to do some rethinking of the meaning of elevations of

arabinose and how that might relate to situations when oxalates are

elevated or become elevated. These situations may cause or be caused by

increases in peroxidation in the gut affecting the community of microbes

there. Some of those microbes possess genes for oxalate oxidase which

produces hydrogen peroxide when it is acting on oxalate. Candida albicans

makes d-erythroascorbic acid from arabinose, and this may be converted to

oxalate when hydrogen peroxide is present.

Here are some key excerpts from some of the articles below:

1. d-erythroascorbic acid is a precursor to oxalate

2. In C. albicans, D-erythroascorbic acid was formed from D-arabinose by

D-arabinose dehydrogenase and D-arabinono-1,4-lactone oxidase

3. Treatment of this galactoside with alkaline hydrogen peroxide produces

oxalic acid as observed earlier with erythroascorbic acid.

[in other words, D-erythroascorbic acid also produces oxalic acid in

the climate of hydrogen peroxide.]

4. [Candida albicans was] found in the layers [of kidney stones]

precipitated with oxalate crystals

5. A chemiluminescent synthetic system (luminol/porphyrin) was

successfully used to measure serum oxalate by determination of hydrogen

peroxide generated through oxalate oxidase (EC 1.2.3.4.)

[This enzyme which is present in some flora generates hydrogen

peroxide in the presence of oxalate.]

6. Citrate protects cells from oxalate and CaOx crystal induced injury by

preventing lipid peroxidation through a decrease in ROS production.

Carbohydr Res. 1999 Oct 15;321(3-4):228-34. Related Articles, Links

The reaction of hyaluronic acid and its monomers, glucuronic acid and

N-acetylglucosamine, with reactive oxygen species.

Jahn M, Baynes JW, Spiteller G.

Lehrstuhl Organische Chemie I, Universitat Bayreuth, Germany.

Synovial fluid is a approximately 0.15% (w/v) aqueous solution of

hyaluronic acid (HA), a polysaccharide consisting of alternating units of

GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid

arthritis, HA is thought to be degraded either by radicals generated by

Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We

investigated the course of model reactions of these two reactants in

physiological buffer with HA, and with the corresponding monomers GlcA and

GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric

acid were identified by GC-MS as oxidation products of glucuronic acid.

When GlcNAc was oxidised, erythronic acid, arabinonic acid,

2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose

were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition,

arabinaric acid and glucaric acid were obtained by oxidation with

Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds

primarily at glucuronic acid residues. meso-Tartaric acid may be a useful

biomarker of hyaluronate oxidation since it is produced by both NaOCl and

Fenton chemistry.

PMID: 10614067 [PubMed - indexed for MEDLINE]

Trends Genet. 2000 Dec;16(12):559-65. Related Articles, Links

Click here to read

Regulation of the L-arabinose operon of Escherichia coli.

Schleif R.

Biology Dept, s Hopkins University, 3400 N. St, Baltimore,

MD 21218, USA. bob@...

Over forty years of research on the L-arabinose operon of Escherichia

coli have provided insights into the mechanism of positive regulation of

gene activity. This research also discovered DNA looping and the mechanism

by which the regulatory protein changes its DNA-binding properties in

response to the presence of arabinose. As is frequently seen in focused

research on biological subjects, the initial studies were primarily

genetic. Subsequently, the genetic approaches were augmented by

physiological and then biochemical studies. Now biophysical studies are

being conducted at the atomic level, but genetics still has a crucial role

in the study of this system.

Publication Types:

* Review

* Review, Tutorial

PMID: 11102706 [PubMed - indexed for MEDLINE]

.. Biochem Biophys Res Commun. 1995 Jul 6;212(1):196-203. Related

Articles, Links

Click here to read

Conversion of D-arabinose to D-erythroascorbic acid and oxalic acid in

Sclerotinia sclerotiorum.

Loewus FA, Saito K, Suto RK, Maring E.

Institute of Biological Chemistry, Washington State University,

Pullman 99164-6340, USA.

D-glycero-Pent-2-enono-1,4-lactone (trivial name: D-erythroascorbic

acid) occurs in the phytopathogen, Sclerotinia sclerotiorum (Lib.) de Bary,

where it has a potential role as precursor of oxalic acid. On

Glc/yeast/malt medium, S. sclerotiorum produces only nominal amounts of

D-erythroascorbic acid but even partial replacement of Glc by D-Ara

increases production of erythroascorbic acid and oxalic acid. Use of

D-[1-14C]-, -[3-14C]-, or -[6-14C]Glc and D-[5-3H]-, -[2-14C,5-3H]-, or

-[uL-14C]Ara provide additional information on erythroascorbic acid

biosynthesis and cleavage. The latter process resembles that obtained by

peroxygenation of erythroascorbic acid in alkaline solution. An unknown

erythroascorbic acid-like compound also occurs in both Glc- and Ara-based

cultures.

PMID: 7612007 [PubMed - indexed for MEDLINE]

Biochim Biophys Acta. 1996 Sep 13;1297(1):1-8. Related Articles, Links

D-arabinose dehydrogenase and biosynthesis of erythroascorbic acid in

Candida albicans.

Kim ST, Huh WK, Kim JY, Hwang SW, Kang SO.

Department of Microbiology, College of Natural Sciences, Seoul

National University, South Korea.

D-Arabinose dehydrogenase was purified 2750-fold from the cytosolic

fraction of Candida albicans to apparent homogeneity, with an overall yield

of 3%, by a purification procedure consisting of ammonium sulfate

precipitation and DEAE-Sepharose A-50, Sephacryl S-200, Cibacron blue and

phenyl-Sepharose CL-4B chromatographies. Gel-filtration chromatography gave

an apparent molecular mass of 41 kDa and SDS-PAGE showed only one protein

band corresponding to a molecular mass of 42 kDa, indicating that the

enzyme is a single polypeptide. The enzyme was optimally active at pH 8.0

and the pI value of the enzyme was 5.0. The enzyme was relatively stable

from pH 4.5 to 7.5. The optimal temperature for the enzyme activity was 30

degrees C. The activity of the enzyme was inhibited by Hg2+, Fe2+, Zn2+,

Cu2+, Mg2+, Mn2+, N-ethylmaleimide and p-chloromercuribenzoic acid. The

enzyme catalysed the oxidation of D-arabinose, L-fucose, L-xylose and

L-galactose, which have the same configurations of hydroxyl groups at C2-

and C3-positions, with apparent K(m) values of 29.2, 28.9, 37.1 and 91.3 mM

at pH 8.0, respectively, with 50 microM NADP+. The enzyme used NADP+ as a

coenzyme. Apparent K(m) value at 60 mM D-arabinose for NADP+ was 44.6

microM. NADPH inhibited the enzyme activity competitively with respect to

NADP+ (Ki = 78.6 microM). The amino-terminal sequence of the enzyme was

Met-Lys-Leu-Ala-Thr-Glu-Ile-Asp-Phe-X-Leu-Asn-Asn-Gly-. The reaction

product was D-arabinono-1,4-lactone, judged from gas-liquid

chromatography/mass spectrometry. In C. albicans, D-erythroascorbic acid

was formed from D-arabinose by D-arabinose dehydrogenase and

D-arabinono-1,4-lactone oxidase.

Urology. 1989 Dec;34(6):385-7. Related Articles, Links

Detection by light microscopy of Candida in thin sections of bladder

stone.

Takeuchi H, Konishi T, Tomoyoshi T.

Department of Urology, Shiga University of Medical Sciences, Japan.

We detected fungi morphologically resembling Candida albicans in an

infected bladder stone by light microscopy of thin sections. The fungi were

found in the layers precipitated with oxalate crystals and were invading

the interstices surrounded with apatite or struvite crystals as in tissue

infection. This presumably represents a superimposed infection due to

changes in flora following treatment with antibiotics.

Publication Types:

* Case Reports

PMID: 2688263 [PubMed - indexed for MEDLINE]

Phytochemistry. 1998 Dec;49(8):2397-401. Related Articles, Links

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5-O-(alpha-D-galactopyranosyl)-D-glycero-pent-2-enono-1,4-lactone:

characterization in the oxalate-producing fungus, Sclerotinia sclerotiorum.

Keates SE, Loewus FA, Helms GL, Zink DL.

Department of Botany, Washington State University, Pullman 99164, USA.

Extracts of sclerotia from Sclerotinia sclerotiorum, a fungal

phytopathogen, contain two electrochemically-active constituents,

D-glycero-pent-2-enono-1,4-lactone (trivial name: D-erythroascorbic acid),

and a previously unidentified compound, here characterized as

5-O-(alpha-D-galactopyranosyl)-D-glycero-pent-2-enono-1,4-lactone on the

basis of its physical and chemical properties and its two hydrolytic

products, D-galactose and D-erythroascorbic acid. Treatment of this

galactoside with alkaline hydrogen peroxide produces oxalic acid as

observed earlier with erythroascorbic acid.

PMID: 9887532 [PubMed - indexed for MEDLINE]

J Biolumin Chemilumin. 1997 Nov-Dec;12(6):295-8. Related Articles,

Links

Chemiluminescent measurement of oxalate in serum by detection of

hydrogen peroxide generated through oxalate oxidase.

Gaulier JM, Steghens JP, Lardet G, Vallon JJ, Cochat P.

Federation de Biochemie, Hopital Edouard Herriot, Lyon, France.

Today, chemiluminescence detection reactions have become popular in

analytical biochemistry essentially due to their high sensitivity. A

chemiluminescent synthetic system (luminol/porphyrin) was successfully used

to measure serum oxalate by determination of hydrogen peroxide generated

through oxalate oxidase (EC 1.2.3.4.). This new method is efficient and

simple, highly sensitive and the results obtained in normal adult subjects

are in good agreement with those of approved methods. This original

application of such a chemiluminescent system allowed us to achieve a

sensitive serum oxalate assay (detection limit of 0.2 mumol/L)

characterized by a low serum volume (200 microL) required for analysis.

PMID: 9509337 [PubMed - indexed for MEDLINE]

: J Urol. 2005 Feb;173(2):640-6. Related Articles, Links

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Citrate provides protection against oxalate and calcium oxalate

crystal induced oxidative damage to renal epithelium.

Byer K, Khan SR.

Department of Pathology, Immunology and Laboratory Medicine,

University of Florida, Gainesville, Florida 32610-0275, USA.

PURPOSE: Oxalate and calcium oxalate (CaOx) crystals are injurious to

renal epithelial cells. The injury is caused by the production of reactive

oxygen species (ROS). Citrate is a well-known inhibitor of CaOx

crystallization and as such it is one of the major therapeutic agents

prescribed. Since citrate increases cellular reduced nicotinamide adenine

dinucleotide phosphate and glutathione (GSH), we hypothesized that

exogenously administered citrate should act as an antioxidant and protect

cells from oxalate induced injury. MATERIALS AND METHODS: We exposed

LLC-PK1 and MDCK cells to 500 microM/ml oxalate or 150 mug/cm calcium

oxalate crystals for 30, 60 and 180 minutes with or without 3 mg/ml citrate

in the medium. We determined cell viability by lactate dehydrogenase

release and trypan blue exclusion, ROS involvement by changes in hydrogen

peroxide and GSH, and lipid peroxidation by quantifying 8-isoprostane.

RESULTS: The presence of citrate was associated with significant decrease

in lactate dehydrogenase release (p <0.001) and staining with trypan blue

(p <0.05). In addition, there was a significant increase in GSH (p <0.005)

and a decrease in the production of hydrogen peroxide (p <0.05) and

8-isoprostane (p <0.0005) secretion into the culture medium when citrate

was present in the medium. CONCLUSIONS: Citrate protects cells from oxalate

and CaOx crystal induced injury by preventing lipid peroxidation through a

decrease in ROS production. The results provide additional data for the

beneficial role of citrate therapy for CaOx nephrolithiasis.

PMID: 15643280 [PubMed - indexed for MEDLINE]

Arch Biochem Biophys. 2005 Jan 1;433(1):176-92. Related Articles,

Links

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The enzymes of oxalate metabolism: unexpected structures and mechanisms.

Svedruzic D, Jonsson S, Toyota CG, Reinhardt LA, Ricagno S, Lindqvist

Y, s NG.

Department of Chemistry, University of Florida, Gainesville, FL

32611-7200, USA.

Oxalate degrading enzymes have a number of potential applications,

including medical diagnosis and treatments for hyperoxaluria and other

oxalate-related diseases, the production of transgenic plants for human

consumption, and bioremediation of the environment. This review seeks to

provide a brief overview of current knowledge regarding the major classes

of enzymes and related proteins that are employed in plants, fungi, and

bacteria to convert oxalate into CO(2) and/or formate. Not only do these

enzymes employ intriguing chemical strategies for cleaving the chemically

unreactive C-C bond in oxalate, but they also offer the prospect of

providing new insights into the molecular processes that underpin the

evolution of biological catalysts.

Publication Types:

* Review

* Review, Tutorial

PMID: 15581576 [PubMed - indexed for MEDLINE]