scholarly journals Equilibrium and kinetic studies of oxygen binding to the haemocyanin from the freshwater snail Lymnaea stagnalis

1983 ◽  
Vol 209 (3) ◽  
pp. 905-905
Keyword(s):  
Lymnaea Stagnalis ◽  
Kinetic Studies ◽  
Freshwater Snail ◽  
Oxygen Binding

scholarly journals Equilibrium and kinetic studies of oxygen binding to fragments of Lymnaea stagnalis (freshwater snail) haemocyanin obtained by proteolytic digestion

1983 ◽  
Vol 209 (2) ◽  
pp. 519-526 ◽  
Author(s):  
A Dawson ◽  
E J Wood
Keyword(s):  
Lymnaea Stagnalis ◽  
Functional Unit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Kinetic Studies ◽  
Freshwater Snail ◽  
Dissociation Rate ◽  
Exchange Chromatography ◽  
Hill Coefficient ◽  
Oxygen Binding ◽  
O2 Binding

Functional fragments of the haemocyanin from the gastropod mollusc Lymnaea stagnalis (freshwater snail) were obtained by partial digestion with trypsin and plasmin. The fragments were purified by ion-exchange chromatography and characterized by detergent/polyacrylamide-gel electrophoresis and crossed immunoelectrophoresis. Three types of single-functional unit fragment were isolated from the trypsin digest, and two immunologically distinct three-functional unit fragments and a single-functional unit fragment were isolated from the plasmin digest. The O2-binding behaviour of the fragments was investigated by equilibrium and kinetic methods. Over the pH range 7.0-8.2, in the presence of 10-20 mM-CaCl2, all of the single-functional unit fragments displayed non-co-operative O2 binding and showed no evidence of a Bohr or a salt effect. A Hill coefficient of less than 1.0 was obtained with one of the two three-functional unit fragments studied, whereas both of these fragments displayed a Bohr effect. Functional heterogeneity of the fragments was indicated by the variation in the O2 affinity, the P50 (partial pressure of O2 at half saturation) ranging between 0.26 and 0.77 kPa (approx. 2-6 mmHg). Stopped-flow data reflected the O2 equilibrium behaviour. Thus there was a fall in the value of the O2 dissociation rate constant from approx. 15 to 1s-1 in parallel with the increase in O2 affinity.

Equilibrium and kinetic studies of oxygen binding by gastropod (Lymnaea stagnalis) haemocyanin

1981 ◽  
Vol 9 (5) ◽  
pp. 446-447 ◽  
Author(s):  
ANNE DAWSON ◽  
DAVID A. BAXENDALE ◽  
EDWARD J. WOOD
Keyword(s):  
Lymnaea Stagnalis ◽  
Kinetic Studies ◽  
Oxygen Binding

THE EFFECTS OF MATING SYSTEM AND GENETIC VARIABILITY ON SUSCEPTIBILITY TO TREMATODE PARASITES IN A FRESHWATER SNAIL, LYMNAEA STAGNALIS

Evolution ◽  
2004 ◽  
Vol 58 (12) ◽  
pp. 2747 ◽  
Author(s):  
Mikael Puurtinen ◽  
Mirjami Hytönen ◽  
K. Emily Knott ◽  
Jouni Taskinen ◽  
Kari Nissinen ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Mating System ◽  
Lymnaea Stagnalis ◽  
Freshwater Snail ◽  
Trematode Parasites

Does water chemistry affect the dietary uptake and toxicity of silver nanoparticles by the freshwater snail Lymnaea stagnalis?

2014 ◽  
Vol 189 ◽  
pp. 87-91 ◽  
Author(s):  
Ana López-Serrano Oliver ◽  
Marie-Noële Croteau ◽  
Tasha L. Stoiber ◽  
Mila Tejamaya ◽  
Isabella Römer ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Water Chemistry ◽  
Lymnaea Stagnalis ◽  
Freshwater Snail ◽  
Dietary Uptake

Fixed phagocytes in the freshwater snail Lymnaea stagnalis

1979 ◽  
Vol 196 (3) ◽  
pp. 545-548 ◽  
Author(s):  
T. Sminia ◽  
W. P. W. van der Knaap ◽  
F. G. M. Kroese
Keyword(s):  
Lymnaea Stagnalis ◽  
Freshwater Snail

scholarly journals Voltage- and Calcium-Dependent Inactivation of Calcium Channels in Lymnaea Neurons

1999 ◽  
Vol 114 (4) ◽  
pp. 535-550 ◽  
Author(s):  
Shalini Gera ◽  
Lou Byerly
Keyword(s):  
Cytochalasin B ◽  
Lymnaea Stagnalis ◽  
Slow Component ◽  
Freshwater Snail ◽  
High Concentration ◽  
Calcium Dependent ◽  
Channel Inactivation ◽  
Dependent Inactivation ◽  
Lymnaea Neurons ◽  
Ca2 Channels

Ca2+ channel inactivation in the neurons of the freshwater snail, Lymnaea stagnalis, was studied using patch-clamp techniques. In the presence of a high concentration of intracellular Ca2+ buffer (5 mM EGTA), the inactivation of these Ca2+ channels is entirely voltage dependent; it is not influenced by the identity of the permeant divalent ions or the amount of extracellular Ca2+ influx, or reduced by higher levels of intracellular Ca2+ buffering. Inactivation measured under these conditions, despite being independent of Ca2+ influx, has a bell-shaped voltage dependence, which has often been considered a hallmark of Ca2+-dependent inactivation. Ca2+-dependent inactivation does occur in Lymnaea neurons, when the concentration of the intracellular Ca2+ buffer is lowered to 0.1 mM EGTA. However, the magnitude of Ca2+-dependent inactivation does not increase linearly with Ca2+ influx, but saturates for relatively small amounts of Ca2+ influx. Recovery from inactivation at negative potentials is biexponential and has the same time constants in the presence of different intracellular concentrations of EGTA. However, the amplitude of the slow component is selectively enhanced by a decrease in intracellular EGTA, thus slowing the overall rate of recovery. The ability of 5 mM EGTA to completely suppress Ca2+-dependent inactivation suggests that the Ca2+ binding site is at some distance from the channel protein itself. No evidence was found of a role for serine/threonine phosphorylation in Ca2+ channel inactivation. Cytochalasin B, a microfilament disrupter, was found to greatly enhance the amount of Ca2+ channel inactivation, but the involvement of actin filaments in this effect of cytochalasin B on Ca2+ channel inactivation could not be verified using other pharmacological compounds. Thus, the mechanism of Ca2+-dependent inactivation in these neurons remains unknown, but appears to differ from those proposed for mammalian L-type Ca2+ channels.

Tissue accumulation of aluminium is not a predictor of toxicity in the freshwater snail, Lymnaea stagnalis

2009 ◽  
Vol 157 (7) ◽  
pp. 2142-2146 ◽  
Author(s):  
Rachel C. Walton ◽  
Catherine R. McCrohan ◽  
Francis R. Livens ◽  
Keith N. White
Keyword(s):  
Lymnaea Stagnalis ◽  
Freshwater Snail ◽  
Tissue Accumulation
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