scholarly journals Reactive Sulphydryl Groups in Horse Carbonmonoxyhaemoglobin

2017 ◽  
Vol 7 (2) ◽  
pp. 96-101
Author(s):  
Omolola E. Omotosho ◽  
Franklyn N. Iheagwam ◽  
Priscilla E. Imion ◽  
Esther O. Idowu ◽  
Peace C. Chinonyere ◽  
...  
Keyword(s):  
Sulphydryl Groups

The Effect of Agonists and Antagonists of Platelet Aggregation on von Willebrand Factor-Mediated Platelet Agglutination

1991 ◽  
Vol 65 (05) ◽  
pp. 573-577 ◽  
Author(s):  
Jean McPherson ◽  
Marjorie B Zucker ◽  
Evelyn A Mauss ◽  
Sandra Brownlea
Keyword(s):  
Receptor Antagonist ◽  
Intracellular Calcium ◽  
Calcium Ions ◽  
Inhibitory Action ◽  
Platelet Rich Plasma ◽  
Cytoskeletal Proteins ◽  
A 23187 ◽  
Sulphydryl Groups ◽  
Affinity Receptor ◽  
Adp Receptor

SummaryRistocetin-induced platelet agglutination (RIPA) in EDTA-treated citrated platelet-rich plasma was reduced to 49 ± 11% by 1.25 ΜM ADP, 41 ± 14% by 1 ΜM A 23187, and 26 ± 7% by 0.1 Μg/ml platelet activating factor (PAF). The effect of 5-110 ΜM epinephrine was not dose-dependent, but varied between donors, with RIPA from 56-100% of the control. The inhibitory effects of these agonists were not altered by prior treatment of platelets with aspirin. Prior addition of 200 ΜM ATP (an ADP receptor antagonist acting at both high and low affinity ADP receptors) prevented the inhibitory action of ADP but not that of A 23187 or PAF, suggesting that the inhibitory actions of the latter are not mediated by released ADP. As 700 ΜM 8-bromoadenosine 5-diphosphate (an ADP receptor antagonist acting mainly at the high affinity receptor) did not prevent ADP-induced inhibition of RIPA, interaction of ADP with the low affinity receptor is presumably responsible for its inhibitory action. As A 23187, but not phorbol myristate acetate (0.1 ΜM) inhibited RIPA, an increase in intracellular calcium ions rather than direct stimulation of protein kinase C appears to mediate agonist-induced inhibition. Cytochalasin B (10.5-21 ΜM), dibucaine (0.5-1 mM), and prostaglandin E1 (25 nM), added before or after the agonist, prevented or reversed ADP-, A23187-, and PAF-induced inhibition of RIPA, suggesting that the state of the platelet cytoskeleton affects inhibition. N-ethylmaleimide (0.25-0.5 mM), an agent that can penetrate cell membranes and block sulphydryl groups, prevented or reversed ADP, A 23187- and PAF-induced inhibition of RIPA, but 0.5 mM dithionitrobisbenzoic acid, a non-penetrating sulphydryl blocker, had no effect. Diamide (0.1-0.5 mM), an agent that can crosslink cytoskeletal proteins by oxidation of sulphydryl groups, reduced RIPA. Thus an increase in intracellular calcium ions with resultant cytoskeletal changes and reorganisation of intracellular sulphydryl groups may mediate the inhibitory action of agonists on RIPA.

IONIC EFFECTS ON THE UPTAKE OF CHLOROMERCURIBENZENE-p-SULPHONIC ACID BY PANCREATIC ISLETS

1977 ◽  
Vol 86 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Monica Söderberg ◽  
Inge-Bert Täljedal
Keyword(s):  
Pancreatic Islets ◽  
Islet Cell ◽  
Choline Chloride ◽  
Inorganic Ions ◽  
Sulphonic Acid ◽  
Cell Uptake ◽  
Β Cells ◽  
Sulphydryl Groups ◽  
Microdissected Pancreatic Islets ◽  
Ionic Effects

ABSTRACT Effects of inorganic ions on the uptake of chloromercuribenzene-p-sulphonic acid (CMBS) were studied in microdissected pancreatic islets of non-inbred ob/ob-mice. Na2SO4 stimulated the total islet cell uptake of CMBS but decreased the amount of CMBS remaining in islets after brief washing with L-cysteine. CaCl2 stimulated both the total and the cysteine-non-displaceable uptake; the stimulatory effect of CaCl2 on the cysteine-non-displaceable CMBS uptake was counteracted by Na2SO4. NaCl, KCl or choline chloride had no significant effect on the total islet cell uptake of CMBS, whereas LiCl was stimulatory. It is concluded that β-cells resemble erythrocytes in having a permeation path for CMBS that is inhibited by SO42−. By analogy with existing models of the erythrocyte membrane, it is suggested that the SO42−-sensitive path leads to sulphydryl groups controlling monovalent cationic permeability in β-cells.

scholarly journals The sulphydryl groups of sickle-cell haemoglobin

1957 ◽  
Vol 65 (4) ◽  
pp. 760-763 ◽  
Author(s):  
V. M. Ingram
Keyword(s):  
Sickle Cell ◽  
Sulphydryl Groups

scholarly journals Autoimmune hypoglycaemia caused by alpha-lipoic acid: a rare condition in Caucasian patients

2018 ◽  
Vol 2018 ◽  
Author(s):  
A Veltroni ◽  
G Zambon ◽  
S Cingarlini ◽  
M V Davì
Keyword(s):  
Lipoic Acid ◽  
Serum Insulin ◽  
Strong Association ◽  
High Serum ◽  
List Type ◽  
Alpha Lipoic Acid ◽  
Hyperinsulinaemic Hypoglycaemia ◽  
C Peptide ◽  
Sulphydryl Groups ◽  
Caucasian Patients

Summary Insulin autoimmune syndrome (IAS), a rare cause of autoimmune hyperinsulinaemic hypoglycaemia, is relatively well known in Japan. The incidence in Caucasians is less than one-fifth of that reported in Japanese people, but it is becoming increasingly recognised worldwide in non-Asians as well. Drugs containing sulphydryl groups are known to be associated with the disease in genetically predisposed individuals. Moreover, several recent reports showed a direct association between the onset of IAS and the consumption of dietary supplements containing alpha-lipoic acid (LA). Insulinoma remains the most prevalent cause of hypersulinaemic hypoglycaemia in Caucasians. Consequently, primary investigation in these patients is generally focused on localisation of the pancreatic tumour, often with invasive procedures followed by surgery. We described a case of an Italian woman presenting to us with severe recurrent hypoglycaemia associated with high insulin and C-peptide levels and no evidence of pancreatic lesions at imaging diagnostic procedures. She had taken LA until 2 weeks before hospitalisation. After an evaluation of her drug history, an autoimmune form of hypoglycaemia was suspected and the titre of insulin autoantibodies was found to be markedly elevated. This allowed us to diagnose LA-related IAS, thus preventing any unnecessary surgery and avoiding invasive diagnostic interventions. Learning points: IAS is a rare cause of hyperinsulinaemic hypoglycaemia that typically affects Asian population, but it has been increasingly recognised in Caucasian patients. It should be considered among the differential diagnosis of hyperinsulinaemic hypoglycaemia to avoid unnecessary diagnostic investigations and surgery. It should be suspected in the presence of very high serum insulin levels (100–10  000  μU/mL) associated with high C-peptide levels. There is a strong association with administration of drugs containing sulphydryl groups included LA, a dietary supplement commonly used in Western countries to treat peripheral neuropathy.

Equilibrium Studies of the Reaction of Turkey (Meleagris gallopavo) Haemoglobin Sulphydryl Groups with 5,5′-dithiobis(2-nitrobenzoate): Tertiary Conformational Change in Turkey Haemoglobin Induced by Inositol hexakisphosphate

2014 ◽  
Vol 4 (4) ◽  
pp. 200-206
Author(s):  
C. O. Ehi-Eromosele ◽  
A. Edobor-Osoh ◽  
C. O. Ajanaku ◽  
W. U. Anake ◽  
O. Aladesuyi ◽  
...  
Keyword(s):  
Conformational Transition ◽  
Ph Dependence ◽  
Meleagris Gallopavo ◽  
Relative Distribution ◽  
Minor Components ◽  
Protein Conformations ◽  
Inositol Hexakisphosphate ◽  
Equilibrium Studies ◽  
Relative Population ◽  
Sulphydryl Groups

The red blood cell of turkey contains two haemoglobin types, major and minor components. In the present study, the equilibrium constant, Kequ, for the reaction of 5,5′-dithiobis(2-nitrobenzoate), DTNB, with the sulphydryl group of the major turkey aquomethaemoglobin was determined at 25°C as a function of pH. Kequ varies by about 2 to 3 orders of magnitude between pH 5.6 and 9.0 for both haemoglobin [stripped and in the presence of inositol hexakisphosphate (inositol-P6)]. Calculations from the pH dependence of Kequ showed that in the r ⇌ t tertiary conformational transition of aquomethae-moglobin, the t isomer population was 0.26 %. In the presence of inositol-P6, the t isomer population increased to 9.08 %. The results showed that while inositol-P6 increased the relative population of the t tertiary conformation by changing the relative distribution of two protein conformations, it had no effect on Kequ. The effect of Inositol-P6 on the nature and number of groups linked to the DTNB reaction was also determined.

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