scholarly journals Quin 2: the dissociation constants of its Ca2+ and Mg2+ complexes and its use in a fluorimetric method for determining the dissociation of Ca2+-protein complexes

1985 ◽  
Vol 226 (2) ◽  
pp. 613-616 ◽  
Author(s):  
D T W Bryant
Keyword(s):  
Vitamin D ◽  
Good Accuracy ◽  
Dissociation Constants ◽  
Protein Complexes ◽  
Binding Protein ◽  
Fluorimetric Method ◽  
Kd Values ◽  
Spectrophotometric Titrations

Fluorimetric or spectrophotometric titrations with the appropriate cations gave Kd values of 2.9 +/- 0.2 nM and 89 +/- 5 microM respectively for the Ca2+ and Mg2+ complexes of quin 2 at pH 7.5. Mixtures of quin 2 and vitamin D-dependent Ca2+-binding protein from pig duodenum were titrated fluorimetrically with Ca2+ in the absence or presence of Mg2+. These measurements were used with the Kd values of the Ca2+ and Mg2+ complexes of quin 2 to obtain Kd or apparent Kd values for Ca2+-protein complexes ranging from 5 nM to 5 microM with good accuracy.

scholarly journals Acyl-CoA-binding protein (ACBP) can mediate intermembrane acyl-CoA transport and donate acyl-CoA for β-oxidation and glycerolipid synthesis

1994 ◽  
Vol 299 (1) ◽  
pp. 165-170 ◽  
Author(s):  
J T Rasmussen ◽  
N J FÆrgeman ◽  
K Kristiansen ◽  
J Knudsen
Keyword(s):  
Dissociation Constants ◽  
Binding Protein ◽  
Nitrocellulose Membrane ◽  
Beta Oxidation ◽  
Titration Microcalorimetry ◽  
Kd Values ◽  
Glycerolipid Synthesis

The dissociation constants for octanoyl-CoA, dodecanoyl-CoA and hexadecanoyl-CoA binding to acyl-CoA-binding protein (ACBP) were determined by using titration microcalorimetry. The KD values obtained, (0.24 +/- 0.02) x 10(-6) M, (0.65 +/- 0.2) x 10(-8) M and (0.45 +/- 0.2) x 10(-13) M respectively, were much lower than expected. ACBP was able to extract hexadecanoyl-CoA from phosphatidylcholine membranes immobilized on a nitrocellulose membrane. The acyl-CoA/ACBP complex formed was able to transport acyl-CoA to mitochondria or microsomes in suspension, or to microsomes immobilized on a nitrocellulose membrane, and to donate them to beta-oxidation or glycerolipid synthesis in mitochondria or microsomes, respectively.

scholarly journals Investigation of the binding of Ca2+, Mg2+, Mn2+ and K+ to the vitamin D-dependent Ca2+-binding protein from pig duodenum

1984 ◽  
Vol 219 (1) ◽  
pp. 287-292 ◽  
Author(s):  
D T W Bryant ◽  
P Andrews
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Cation Binding ◽  
Binding Studies ◽  
Binding Properties ◽  
Kd Values ◽  
Significant Difference ◽  
The One ◽  
Fluorimetric Titration ◽  
Flow Dialysis

The cation-binding properties of the vitamin D-dependent Ca2+-binding protein from pig duodenum were investigated, mainly by flow dialysis. The protein bound two Ca2+ ions with high affinity, and Mg2+, Mn2+ and K+ were all bound competitively with Ca2+ at both sites. The sites were distinguished by their different affinities for Mn2+, the one with the higher affinity being designated A (Kd 0.61 +/- 0.02 microM) and the other B (Kd 50 +/- 6 microM). Competitive binding studies allied to fluorimetric titration with Mg2+ showed that site A bound Ca2+, Mg2+ and K+ with Kd values of 4.7 +/- 0.8 nM, 94 +/- 18 microM and 1.6 +/- 0.3 mM respectively, and site B bound the same three cations with Kd values of 6.3 +/- 1.8 nM, 127 +/- 38 microM and 2.1 +/- 0.6 mM. For the binding of these cations, therefore, there was no significant difference between the two sites. In the presence of 1 mM-Mg2+ and 150 mM-K+, both sites bound Ca2+ with an apparent Kd of 0.5 microM. The cation-binding properties were discussed relative to those of parvalbumin, troponin C and the vitamin D-dependent Ca2+-binding protein from chick duodenum.

Studies on vitamin D binding protein in the nephrotic syndrome.

1985 ◽  
Vol 31 (5) ◽  
pp. 718-721 ◽  
Author(s):  
K Colston ◽  
N J Williams ◽  
H J Cleeve
Keyword(s):  
Vitamin D ◽  
Nephrotic Syndrome ◽  
Gradient Analysis ◽  
Dissociation Constants ◽  
Binding Capacity ◽  
Specific Binding ◽  
Binding Protein ◽  
Normal Subjects ◽  
Sucrose Density Gradient ◽  
Vitamin D Binding Protein

Abstract We studied the properties of vitamin D binding protein in plasma and urine from nine patients with nephrotic syndrome. Samples were incubated with 25-[3H]hydroxyvitamin D3, after which we determined binding capacity and apparent dissociation constants. Binding capacity was markedly less in plasma from patients with nephrotic syndrome than that from normal subjects, but binding affinity was unchanged. Specific binding of 25-hydroxy[3H]vitamin D3 could be demonstrated in urine from all the nephrotic patients, and sucrose density-gradient analysis of these urines revealed a single binding peak with sedimentation characteristics similar to those of vitamin D binding protein in plasma.

Vitamin D binding protein (DBP) is required for pro-invasion effects of vitamin D on placental trophoblastic cells

2019 ◽  
Author(s):  
Ankana Ganguly ◽  
Alexandra Shattock ◽  
Annsha Joseph ◽  
Janesh Gupta ◽  
Martin Hewison
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Vitamin D Binding Protein ◽  
Trophoblastic Cells

scholarly journals Vitamin D receptor, vitamin D binding protein and CYP27B1 single nucleotide polymorphisms and susceptibility to viral infections in infants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Zacharioudaki ◽  
Ippokratis Messaritakis ◽  
Emmanouil Galanakis
Keyword(s):  
Vitamin D ◽  
Single Nucleotide Polymorphisms ◽  
Viral Infection ◽  
Vitamin D Receptor ◽  
Viral Infections ◽  
Binding Protein ◽  
Genotypic Differences ◽  
Nucleotide Polymorphisms ◽  
Vitamin D Binding Protein ◽  
Single Nucleotide

AbstractThe role of vitamin D in innate and adaptive immunity is recently under investigation. In this study we explored the potential association of genetic variances in vitamin D pathway and infections in infancy. Τhis prospective case–control study included infants 0–24 months with infection and age-matched controls. The single nucleotide polymorphisms of vitamin D receptor (VDR) gene (BsmI, FokI, ApaI, TaqI), vitamin D binding protein (VDBP) (Gc gene, rs7041, rs4588) and CYP27B1 (rs10877012) were genotyped by polymerase chain reaction-restriction fragment length polymorphism. In total 132 infants were enrolled, of whom 40 with bacterial and 52 with viral infection, and 40 healthy controls. As compared to controls, ΤaqI was more frequent in infants with viral infection compared to controls (p = 0.03, OR 1.96, 95% CI 1.1–3.58). Moreover, Gc1F was more frequent in the control group compared to infants with viral infection (p = 0.007, OR 2.7, 95% CI 1.3–5.6). No significant differences were found regarding the genetic profile for VDR and VDBP in infants with bacterial infection compared to the controls and also regarding CYP27B1 (rs10877012) between the studied groups. Genotypic differences suggest that vitamin D pathway might be associated with the host immune response against viral infections in infancy.

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