| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-172 |
Sentence |
denotes |
Characterisation in vivo of the reactive thiol groups of the lactose permease from Escherichia coli and a mutant; exposure, reactivity and the effects of substrate binding. |
| T2 |
173-425 |
Sentence |
denotes |
The reactivity and accessibility of the reactive thiol groups of the native lactose permease and a mutant have been studied in a number of circumstances and with a number of reagents, in particular using the specific thiol-disulphide exchange reaction. |
| T3 |
426-564 |
Sentence |
denotes |
Seven different reactive states of the thiol in the native protein have been characterised by their different second-order rate constants. |
| T4 |
565-684 |
Sentence |
denotes |
Interconversion between these states is dependent on the magnitude of the protonmotive force, pH and substrate binding. |
| T5 |
685-780 |
Sentence |
denotes |
In the absence of galactoside, reactivity is controlled by an ionisation with apparent pKa 9.3. |
| T6 |
781-891 |
Sentence |
denotes |
This pKa is not affected by the protonmotive force, but it is lowered in the presence of external galactoside. |
| T7 |
892-1072 |
Sentence |
denotes |
The conformation adopted by the permease when in equilibrium with saturating galactoside appears to be different from that of the intermediate that accumulates during net turnover. |
| T8 |
1073-1185 |
Sentence |
denotes |
In the former state, the reactivity of the thiol group is depressed, whereas in the latter state it is enhanced. |
| T9 |
1186-1332 |
Sentence |
denotes |
The thiol group of the native protein is buried in a hydrophobic environment that has a dielectric constant considerably lower than that of water. |
| T10 |
1333-1478 |
Sentence |
denotes |
The environment is not greatly perturbed by changes in the magnitude of the protonmotive force, but it is affected by the binding of galactoside. |
| T11 |
1479-1634 |
Sentence |
denotes |
In a strain which carries the YUN mutation (Wilson, T.H. and Kusch, M. (1972) Biochim. Biophys. Acta 255, 786-797), two reactive thiols were characterised. |
| T12 |
1635-1803 |
Sentence |
denotes |
The more reactive of the two is more exposed than the thiol group of the native molecule and is in an environment that has a dielectric constant close to that of water. |
| T13 |
1804-1893 |
Sentence |
denotes |
The less reactive thiol appears to be more deeply buried than that of the native protein. |
| T14 |
1894-2083 |
Sentence |
denotes |
Thus the mutation appears to produce a conformation change in the central portion of the polypeptide chain that results in greater exposure of the reactive thiol to the aqueous environment. |
