Sulphydryl Oxidation in the Mechanism of Molecular-Weight Conversion of Renin in Dog Kidney

1982 ◽  
Vol 62 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Fumihiko Ikemoto ◽  
Kazuo Takaori ◽  
Hiroshi Iwao ◽  
Kenjiro Yamamoto
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Renal Cortex ◽  
Soluble Fraction ◽  
Low Molecular Weight ◽  
Oxidizing Agent ◽  
Nitrobenzoic Acid ◽  
Binding Substance ◽  
Sh Group ◽  
Dog Kidney

1. A high-molecular-weight renin (Mr 60 000) was formed by the reaction of a low-molecular-weight renin (Mr 40 000) with a renin-binding substance in canine renal cortical extract in the presence of the sulphydryl (SH) group oxidizing agent potassium tetrathionate; thus the reaction required SH oxidation. 2. Renin extracted from isolated renin granules was adsorbed on to thiopropyl Sepharose 6B, and then liberated with dithiothreitol (50 mmol/l), indicating that it possessed on SH moiety(s). 3. However, the renin was capable of reaction with the renin-binding substance even after its SH moiety (or moieties) was protected with 5,5′-dithiobis-(2-nitrobenzoic acid). 4. The high-molecular-weight renin was converted into the low-molecular-weight renin by incubation (37°C, 15 min) with cytosol (soluble fraction) of renal cortex and liver. Such converting ability was diminished after the cytosol was treated with perchloric acid or potassium tetrathionate. 5. These results suggest that the reaction of renin with the renin-binding substance does not require disulphide bond(s) and that an enzymelike substance which is sensitive to SH oxidation is involved in the conversion from the high-molecular-weight renin into the low-molecular weight renin.

Subcellular Distribution of Low- and High Molecular-Weight Renin and its Relation to a Renin Inhibitor in Pig Renal Cortex

1980 ◽  
Vol 59 (5) ◽  
pp. 337-345 ◽  
Author(s):  
G. A. Sagnella ◽  
P. R. B. Caldwell ◽  
W. S. Peart
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Subcellular Distribution ◽  
Renal Cortex ◽  
Soluble Fraction ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Main Peak ◽  
Low Molecular Weight ◽  
Molecular Weight Form

1. The subcellular distribution of low-molecular-weight and high-molecular weight forms of pig renin has been investigated. 2. Renin, in aqueous extracts of a ‘renin granular fraction’ prepared by differential centrifugation, after gel filtration on Sephadex G-100 displayed an apparent molecular weight of 40 000 and was not activated by acidification to pH 2.8. 3. Renin in the soluble fraction separated on Sephadex G-100 at neutral pH displayed a main peak of activity with an apparent molecular weight of 40000. When eluates were acidified to pH 2.8 (2°C, 60 min) a marked increase in renin activity was observed in the region corresponding to an apparent molecular weight of 50 000. 4. A renin inhibitory material was isolated from the soluble fraction by DEAE chromatography. This material displayed an apparent molecular weight of 50000 and it was destroyed by acidification to pH 2.8. 5. The presence of the proteolytic inhibitor N-ethylmaleimide yielded an apparently high-molecular-weight form of renin (60000–70000) from the soluble fraction, but this was not found in the granular fraction. 6. We conclude that pig renal renin is stored within membrane-bounded subcellular organelles as the low-molecular-weight form. High-molecular-weight renin and renin inhibitory activity are localized to the cortical soluble fraction. In addition, the soluble fraction contains a material which in the presence of N-ethylmaleimide results in the formation of an apparently high-molecular-weight renin.

Interconversion between High- and Low-Molecular-Weight Forms of Renin in Dog Kidney

1980 ◽  
Vol 59 (s6) ◽  
pp. 25s-27s ◽  
Author(s):  
K. Yamamoto ◽  
F. Ikemoto ◽  
M. Kawamura ◽  
K. Takaori
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Apparent Molecular Weight ◽  
Kidney Cortex ◽  
Low Molecular Weight ◽  
Cytosol Fraction ◽  
High Molecular Weight Form ◽  
Binding Substance ◽  
Dog Kidney ◽  
Molecular Weight Form

1. The low-molecular-weight (40 000) form of renin was converted into the high-molecular-weight (60 000) form of renin with sulphydryl oxidation, and the high-molecular-weight form of renin was re-converted into the low-molecular-weight form with a reduction of disulphide bonds in the renal cortical homogenate of the dog. Therefore, the low- and high-molecular-weight forms of renin were interconvertible. 2. The formation of high-molecular-weight form of renin required a renin binding substance which was found to be included in the cytosol fraction of kidney cortex of the dog. 3. The renin binding substance of the dog was unstable to heat and low pH, but vitally resistant to Triton X-100 and chloroform. It did not bind to concanavalin A Sepharose 4B. 4. The renin binding substance was eluted in the molecular-weight region between 156 000 and 60 000 on Sephadex G-200, and such apparent molecular weight was not altered by urea at 4 mol/l; thus molecular weight greater than the theoretically expected value of 20 000 was indicated.

Immunoaffinity Chromatography of Canine High-Molecular-Weight Renin: Partial Purification and Characterization

1983 ◽  
Vol 65 (2) ◽  
pp. 117-120 ◽  
Author(s):  
Fumihiko Ikemoto ◽  
Victor J. Dzau ◽  
Edgar Haber ◽  
Kazuo Takaori ◽  
Kenjiro Yamamoto
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Specific Activity ◽  
Immunoaffinity Chromatography ◽  
Partial Purification ◽  
Low Molecular Weight ◽  
Specific Method ◽  
Disulphide Bonds ◽  
Binding Substance ◽  
Molecular Weight Form

1. Canine high-molecular-weight renin (mol. wt. 60 000) is believed to be a complex of renin (low-molecular-weight form, mol. wt. 40 000) and renin-binding substance. The immunocross-reactivity of high-molecular-weight renin and low-molecular-weight renin was demonstrated by using antibodies specific to low-molecular-weight renin. 2. Immunoaffinity chromatography with renin-specific antibodies coupled to Sepharose provided a simple and specific method for isolation of high-molecular-weight renin. High-molecular-weight renin with a specific activity of 137 600 ng of ANG I h−1 mg−1 of protein (19.6 Goldblatt units/mg of protein) was obtained. 3. This high-molecular-weight renin was stable in dithiothreitol (25 mmol/l), suggesting that disulphide bonds may not be involved in the binding mechanism between low-molecular-weight renin and renin-binding substance. 4. However, exposure to low pH (3.0) resulted in conversion of high-molecular-weight renin into the low-molecular-weight form.

scholarly journals Conversion between renin and high-molecular-weight renin in the dog

1978 ◽  
Vol 176 (3) ◽  
pp. 977-981 ◽  
Author(s):  
S Funakawa ◽  
Y Funae ◽  
K Yamamoto
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Soluble Fraction ◽  
The Other ◽  
Kidney Cortex ◽  
Thiol Groups ◽  
Cortical Tissue ◽  
Neutral Ph ◽  
Dog Kidney ◽  
Renal Cortical Tissue

Two forms of renin, one of mol.wt. 43,000 and the other 60,000, were found in the dog kidney. Conversion between the two forms of renin was reversible at neutral pH. Though the molecular weight of renin in kidney-cortex homogenate was 43,000, it was completely converted into high-molecular-weight renin in the presence of substances that react with thiol groups. On the contrary, stored renin in the granules was the form of normal size (mol. wt. 43,000) regardless of the absence or presence of such substances. The present experiments indicated that renin is stored in the granules as the form of normal size and might be converted into high-molecular-weight renin when it is released from the granules and attached to some substance in the soluble fraction of renal-cortical tissue.

Preliminary Evidence for the Conversion of Dog Renin into a Higher—Molecular—Weight Form by Cold Storage

1980 ◽  
Vol 58 (6) ◽  
pp. 451-456 ◽  
Author(s):  
Minoru Kawamura ◽  
Fumihiko Ikemoto ◽  
Kenjiro Yamamoto
Keyword(s):  
Molecular Weight ◽  
Cold Storage ◽  
Soluble Fraction ◽  
Gel Filtration ◽  
Molecular Size ◽  
Preliminary Evidence ◽  
Concomitant Increase ◽  
Binding Substance ◽  
Dog Kidney ◽  
Molecular Weight Form

1. A soluble fraction of renal cortical homogenate (cytosol) and renin extracted from isolated renin granules of the dog kidney were kept at 0°C. 2. Although the molecular weight of the renin in the cytosol on day 1 was estimated to be about 40 000 by gel filtration, the renin was completely converted into a higher—molecular—weight form (60 000) by day 7. The renin in the granules kept its molecular size of 40 000 during cold storage. 3. This type of molecular—weight conversion could be performed without protease inhibitors. 4. Dithiothreitol neither inhibited the conversion into the higher—molecular—weight form of renin during cold storage nor led to a reduction in the molecular weight of renin, although the oxidation of thiol groups has been proposed as the mechanism for the molecular—weight conversion of renin. 5. Keeping a mixture of renin from the granules and crude renin—binding substance at 0°C for 7 days resulted in the conversion of the renin into the higher—molecular—weight form, indicating that the renin—binding substance we have previously described is required for the conversion during cold storage. 6. Acidification caused the higher—molecular—weight form of renin formed in the cytosol to change to the lower—molecular—weight form, with a concomitant increase in activity of about 50%.

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

scholarly journals Antiparasitic antibodies occur with similar frequency in patients with clinically established multiple sclerosis with or without oligoclonal bands in the cerebrospinal fluid

2013 ◽  
Vol 71 (8) ◽  
pp. 512-515 ◽  
Author(s):  
Fabiana Cruz Gomes da Fonseca-Papavero ◽  
Dagoberto Callegaro ◽  
Paulo Diniz da Gama ◽  
Jose Antonio Livramento ◽  
Adelaide Jose Vaz ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Hygiene Hypothesis ◽  
Oligoclonal Bands ◽  
Parasitic Infections ◽  
Low Molecular Weight ◽  
Serum Samples ◽  
Similar Frequency ◽  
Electrophoresis Of Proteins

The "hygiene hypothesis" postulates an inverse relationship between the prevalence of parasitic infections and the frequency of multiple sclerosis (MS). Objective: It was to study whether antibodies against parasites could be demonstrated more frequently in blood serum from MS patients with oligoclonal bands (OCB) than from MS patients without OCB. Methods: We studied serum samples from 164 patients who had previously been analyzed to investigate OCB. Parasitic antibodies were studied through unidimensional electrophoresis of proteins on polyacrylamide gel against Taenia antigens, searching for antiparasitic specific low molecular weight antibodies and also for antiparasitic nonspecific high molecular weight antibodies. Results: Two of the 103 patients with no evidence of OCB had antibodies of low molecular weight and 59 of them had antibodies of high molecular weight. Of the 61 patients with evidence of OCB, one showed antibodies of low molecular weight and 16 showed antibodies of high molecular weight. Conclusion: Antiparasitic antibodies are detected with similar frequency in MS patients with OCB and in MS patients without OCB.

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