Heat Stability Studies on Chelates from Schiff Bases and Polyazines of Salicylaldehyde Derivatives1

1959 ◽  
Vol 81 (11) ◽  
pp. 2668-2670 ◽  
Author(s):  
C. S. Marvel ◽  
P. V. Bonsignore
1957 ◽  
Vol 190 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Wayne M. Meyers ◽  
Kenneth L. Burdon

The incubation of guinea pig serum with a streptokinase-human plasminogen preparation (from purified plasminogen) activates a proteolytic enzyme in the guinea pig serum. Optimal conditions for activity, kinetics, Km values and heat stability of elements of this system were studied. The proteolytic activity of this system was strongly inhibited by lysine ethyl ester and p-toluenesulfonylarginine methyl ester, apparently in a competitive manner. Serum dilution activity curves suggest the presence in guinea pig serum of dissociable protease inhibitors. The proteolytic activity of human plasmin does not appear to be essential for the activation of guinea pig protease, as indicated by heat stability studies. Possible mechanisms of activation are discussed. A survey of other animal species showed the widespread presence of serum proteases which could be activated with streptokinase-human plasminogen mixtures. The human activator systems may prove to be a useful tool in experimental studies of the physiological significance of the protease system.


1954 ◽  
Vol 86 (2) ◽  
pp. 387-390 ◽  
Author(s):  
H. Jensen ◽  
E. J. Gray ◽  
E. H. Schaefer

2012 ◽  
Vol 25 (3) ◽  
pp. 324-336 ◽  
Author(s):  
Ayesha Kausar ◽  
Syed Tajammul Hussain

Genetics ◽  
1974 ◽  
Vol 78 (4) ◽  
pp. 1157-1172
Author(s):  
Edward M Berger

ABSTRACT In vitro enzyme hybridization was carried out with combinations of six allozymic variants of Esterase-5 from Drosophila pseudoobscura. Studies on heat stability and specific activity changes accompanying hybridization were done to examine the possible expression of overdominance at the biochemical level. In 11 of 15 combinations no significant change in specific activity was found following hybridization. In two cases hybridization resulted in a decrease in activity in the mixture, while in two cases esterase activity was elevated. Heat stability studies, in several cases, revealed reduced rates of inactivation in in vitro and in vivo heterozygotes compared with homozygotes. From these and other data a model for the molecular mechanism of heterosis is presented.


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