Dissociation Constant of Acetic Acid in Deuterium Oxide from 5 to 50°. Reference Points for a pD Scale

1965 ◽  
Vol 69 (8) ◽  
pp. 2750-2753 ◽  
Author(s):  
Robert Gary ◽  
Roger G. Bates ◽  
R. A. Robinson
Keyword(s):  
Acetic Acid ◽  
Dissociation Constant ◽  
Deuterium Oxide ◽  
Reference Points

THE DISSOCIATION CONSTANT OF ACETIC ACID FROM 0 TO 35° CENTIGRADE1

1932 ◽  
Vol 54 (4) ◽  
pp. 1350-1357 ◽  
Author(s):  
Herbert S. Harned ◽  
Russell W. Ehlers
Keyword(s):  
Acetic Acid ◽  
Dissociation Constant

Limiting Mobilities of some Monovalent Ions and the Dissociation Constant of Acetic Acid at 25°

Nature ◽  
1933 ◽  
Vol 131 (3297) ◽  
pp. 27-28
Author(s):  
A. I. VOGEL ◽  
G. H. JEFFERY
Keyword(s):  
Acetic Acid ◽  
Dissociation Constant ◽  
Monovalent Ions

scholarly journals A reaction of glucose with peptides

1972 ◽  
Vol 129 (1) ◽  
pp. 203-208 ◽  
Author(s):  
Henry B. F. Dixon
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Blood Glucose ◽  
Dissociation Constant ◽  
Electrophoretic Mobility ◽  
Chemical Properties ◽  
Amino Group ◽  
Half Time ◽  
N Terminus ◽  
And Chemical Properties

Valylhistidine (Val-His) reacts with glucose (Glc) in a mixture of pyridine and acetic acid to form glucosylvalylhistidine (Glc-Val-His). The pK of the α-amino group is thereby lowered to about 5.6 as judged by electrophoretic mobility. The reaction: [Formula: see text] also occurs in an aqueous solution of pyridine and acetic acid of pH6.2 at 50°C, in which it exhibits a half-time of about 30h and a dissociation constant of about 0.3m. Isoleucyltyrosine and glucose react similarly in aqueous solution. The Glc-Val-His has the chromatographic, electrophoretic and chemical properties reported by Holmquist & Schroeder (1966a) for the substance released by proteolysis from the N-terminus of the β-chains of haemoglobin AIc; the value of the dissociation constant means that the concentration of haemoglobin AIc found naturally could be explained by reaction of haemoglobin A with the blood glucose.

Stereochemistry of isopentenyl pyrophosphate isomerase

1972 ◽  
Vol 182 (1068) ◽  
pp. 277-295 ◽  
Keyword(s):  
Acetic Acid ◽  
Deuterium Oxide ◽  
Mevalonic Acid ◽  
Methyl Groups ◽  
Farnesyl Pyrophosphate ◽  
Soluble Enzyme ◽  
Pig Liver ◽  
Isopentenyl Pyrophosphate ◽  
Prototropic Isomerization ◽  
Preliminary Communication

Mevalonic acid stereospecifically labelled with tritium in the 2-position was incubated, in a deuterium oxide medium containing adenosine triphosphate, with a soluble enzyme pre­paration from pig liver; and so converted into farnesyl pyrophosphate. This was hydrolysed enzymically to farnesol which was oxidized, by ozone followed by sodium hypoiodite, to acetic acid originating from the terminal isopropylidene group of farnesol. The tritium in this acetic acid was found, on analysis by a recently developed enzymic method, to be present largely in chiral methyl groups the chirality of which was R or S according to the chirality at C-2 of the parent mevalonic acid. It is deduced that these chiral methyl groups were formed on the enzyme isopentenyl pyrophosphate isomerase, by addition of a deuteron from the medium to the 3 re , 4 re face of the double bond in isopentenyl pyrophosphate. The stereo­chemical relationship between the added and abstracted hydrogen in the prototropic isomerization mediated by this enzyme is thereby established. A preliminary communication of these results has been made (Clifford, Cornforth, Mallaby & Phillips 1971).

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