Truncated hemoglobins in Frankia CcI3: effects of nitrogen source, oxygen concentration, and nitric oxide

2009 ◽  
Vol 55 (7) ◽  
pp. 867-873 ◽  
Author(s):  
Vanessa Coats ◽  
Christa R. Schwintzer ◽  
John D. Tjepkema
Keyword(s):  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
No Oxidation ◽  
Constant Ratio ◽  
Low Oxygen ◽  
Frankia Strain ◽  
Total Hemoglobin ◽  
Truncated Hemoglobins ◽  
Strain Cci3

Frankia strain CcI3 produces 2 truncated hemoglobins, HbN and HbO. Using ion-exchange chromatography, we characterized the expression of the relative amounts of HbN and HbO in −N (nitrogen-fixing) cultures and +N (nitrogen-supplemented) cultures. The −N cultures maintained an approximately constant ratio of HbO to HbN throughout the life of the culture, with HbO constituting 80%–85% of the total hemoglobin produced. In contrast, in +N cultures, HbN was observed to increase over time and HbO decreased. Total hemoglobin as a fraction of total protein was approximately constant throughout the growth phase in −N cultures, while it decreased somewhat in +N cultures. Subjecting −N cultures to a NO generator resulted in increased production of HbN, relative to the controls. Nitrite accumulated in +N cultures, but not in −N cultures. This suggests that the greater amount of HbN in +N cultures might be due to NO produced by the reduction of nitrite. The effects of O2 concentration were determined in +N cultures. Cultures grown in 1% O2 produced about 4 times more HbO than cultures grown in 20% O2. Overall, these results provide evidence for a role of HbN in NO oxidation and for a role of HbO in adaptation to low oxygen concentrations.

scholarly journals Studies on the protein-bound chondroitin sulphate of bovine cortical bone

1968 ◽  
Vol 107 (1) ◽  
pp. 41-49 ◽  
Author(s):  
G. M. Herring
Keyword(s):  
Ion Exchange ◽  
Cortical Bone ◽  
Chondroitin Sulphate ◽  
Bone Sialoprotein ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Mild Conditions ◽  
The Third ◽  
Apparent Homogeneity

A fraction containing chondroitin sulphate, isolated from bovine cortical bone under mild conditions, was separated by ion-exchange chromatography into three fractions with apparent homogeneity on electrophoresis and ultracentrifugation. Two of these appeared to consist of chondroitin sulphate bound to a glycoprotein ‘core’ that had similarities to the bone sialoprotein described previously. The differences in composition of the two fractions were considered to be due to variation in the number or lengths of the polysaccharide chains. The presence of xylose and the alkali-lability of the bond between protein and polysaccharide suggested the presence of a xylosylserine linkage. The third fraction had the properties of a relatively pure chondroitin sulphate which contained a small amount of peptide. These fractions differed considerably from the protein–polysaccharide complexes of epiphysial and other cartilages, and their relevance to the possible role of glycosaminoglycans is discussed.

Role of Methionine in the Initiation of the Biosynthesis of Bovine Proinsulin

1973 ◽  
Vol 51 (6) ◽  
pp. 783-788 ◽  
Author(s):  
C. C. Yip ◽  
C. C. Liew
Keyword(s):  
Amino Acid ◽  
Ion Exchange ◽  
Defined Medium ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Edman Degradation ◽  
Tissue Slices ◽  
Fetal Bovine ◽  
Bovine Pancreas

Slices of fetal bovine pancreas were used to study the initiation of proinsulin biosynthesis. The pancreatic slices were incubated with radioactive methionine, phenylalanine, or leucine, in a defined medium. The incorporation of amino acid into peptides in the tissue slices was measured for 2–3 h. Two types of radioactive peptides, "free" and "blocked," were identified by ion-exchange chromatography. Most of the radioactive "blocked" peptides labelled with [3H]phenylalanine and [35S]methionine were hydrolyzed by proteases, except for about 20% of those labelled with [35S]methionine, which also showed higher resistance to acid hydrolysis.Microsomes were isolated from the tissue slices after incubation and were extracted with acid alcohol. The radioactive proteins in the extract were reacted with a solid immunosorbant against insulin. Analysis of the immunoadsorbed radioactive peptides by Edman degradation showed the presence of both methionine and phenylalanine as the N-termini. It was concluded that methionine was an initiating amino acid in the biosynthesis of bovine proinsulin.

Determination of lignans and isoflavonoids in human female plasma following dietary supplementation

1994 ◽  
Vol 142 (2) ◽  
pp. 251-259 ◽  
Author(s):  
M S Morton ◽  
G Wilcox ◽  
M L Wahlqvist ◽  
K Griffiths
Keyword(s):  
Mass Spectrometry ◽  
Dietary Supplementation ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Soya Flour ◽  
Human Female ◽  
Asian Populations

Abstract Plasma levels of the lignans enterodiol and enterolactone, and also the isoflavonic phyto-oestrogens daidzein, equol and genistein, are reported for postmenopausal Australian women consuming a traditional diet supplemented with linseed, soya flour or clover sprouts. Analysis was performed by gas chromatography-mass spectrometry, after enzymatic hydrolysis and ion-exchange chromatography. Following linseed supplementation, combined levels of enterolactone and enterodiol reached 500 ng/ml, whereas after soya flour or clover sprouts the respective concentrations of equol, daidzein and genistein reached 43, 312 and 148 ng/ml. Not all subjects were able to produce equol from daidzein. The possible relationship and role of these weak dietary oestrogens as restraining factors in the development of hormone-dependent cancers in Asian populations is discussed. Journal of Endocrinology (1994) 142, 251–259

scholarly journals Nitric Oxide and Oxygen Regulate Truncated Hemoglobin Gene Expression in Frankia Strain CcI3

2008 ◽  
Vol 190 (23) ◽  
pp. 7864-7867 ◽  
Author(s):  
James Niemann ◽  
Louis S. Tisa
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Nitrosative Stress ◽  
Fold Increase ◽  
Low Oxygen ◽  
Truncated Hemoglobin ◽  
Frankia Strain ◽  
Hemoglobin Gene ◽  
Oxygen Conditions ◽  
Strain Cci3

ABSTRACT The Frankia genome contains two truncated hemoglobin genes (hboN and hboO) whose functions remain to be determined. Nitric oxide (NO) generated by the addition of 400 μM SNAP (S-nitroso-N-acetylpenicillamine) caused a 10-fold increase in hboN gene expression but had no effect on hboO expression. The addition of the NO scavenger, carboxy-PT10, reduced the effect of SNAP. hboO gene expression increased under low-oxygen conditions, while hboN expression was unaffected. These results suggest that HboN may function in protection from nitrosative stress and that HboO may act as an oxygen transport molecule for increased respiration in hypoxic environments.

scholarly journals A study of the role of metallothionein in the inherited copper toxicosis of dogs

1986 ◽  
Vol 236 (2) ◽  
pp. 409-415 ◽  
Author(s):  
D M Hunt ◽  
S A Wake ◽  
J F B Mercer ◽  
D M Danks
Keyword(s):  
Ion Exchange ◽  
Liver Tissue ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Copper Accumulation ◽  
Total Liver ◽  
Liver Copper ◽  
Rna Blots ◽  
Dog Liver

The role of metallothionein (MT) was assessed in the copper-loading disease prevalent in Bedlington terriers. Fractionation of tissue supernatants over Sephadex G-75 showed that most of the additional cytosolic copper present in liver tissue of these dogs was bound to MT, and that substantially more MT-bound copper could be solubilized by detergent plus mercaptoethanol. Zinc contents were only slightly raised, although most of the extra zinc was associated with a 4000-Mr ligand. Ion-exchange chromatography revealed two isoproteins, MT1 and MT2, in all the dog liver samples examined. In Bedlington terrier liver, copper associated with both isoproteins was increased, although the increase for MT2 was greater than for MT1. The content of MT protein was also raised, although cell-free translations and RNA blots of total liver RNA showed that this increase was not associated with a rise in MT mRNA. The significance of these results to the mechanism of copper accumulation in the Bedlington terrier disorder is discussed.

Improvements in hemoglobin AI determination by rapid cation-exchange chromatography.

1980 ◽  
Vol 26 (8) ◽  
pp. 1209-1212 ◽  
Author(s):  
P G Rand ◽  
C Nelson
Keyword(s):  
Ionic Strength ◽  
Ion Exchange ◽  
Reference Method ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Cation Exchange Chromatography ◽  
Elution Volume ◽  
Total Hemoglobin ◽  
Hemoglobin Ai ◽  
Hemoglobin A1

Abstract The accuracy of many convenient methods for determining the proportion of hemoglobin AI to total hemoglobin by ion-exchange chromatography is in question because those methods have not been evaluated against a reference method. In addition, several if not all of these tests are influenced by laboratory temperature. We modified the chromatographic conditions usually used, to arrive at a method that gives results that agree well with those by the Trivelli method (N. Engl. J. Med. 284, 353, 1971) and is less influenced by ambient temperature than are results obtained with the commercially available Helena and Isolab kits. We accomplished this by lowering the pH of the fast-hemoglobin eluting buffer, with a corresponding adjustment in the ionic strength. We also use a larger elution volume, which assures more nearly complete elution of the hemoglobin A1 fraction. The final method (y) agreed being y = 0.98x + 0.63 r2 = 0.887. Average results from the Helena and Isolab methods were lower than with the reference method by 1.58 and 3.03% hemoglobin A1, respectively.

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