Theoretical interpretation of the decrease of activity of enzyme during its chemical modification

1986 ◽  
Vol 51 (10) ◽  
pp. 2271-2279
Author(s):  
Vladimír Kéry
Keyword(s):  
Amino Acid ◽  
Chemical Modification ◽  
Essential Amino Acid ◽  
The Other ◽  
Theoretical Interpretation ◽  
Amino Acid Residues ◽  
Nonlinear Regression Analysis ◽  
Chemical Modifications ◽  
Cooperative Effects ◽  
The One

A mathematical description of the decrease of the activity of enzyme during its chemical modification, based on probability theory as well as on chemical kinetics and considering both stochastically independent as well as stochastically dependent chemical modifications of any number of essential amino acid residues of the enzyme is proposed. Two types of the stochastically dependent chemical modifications, i.e. with negative cooperative effects and with positive cooperative effects were studied. A direct correlation was found to exist between the relative decrease of enzyme activity on the one hand and the number of essential amino acid residues as well as their role and relative mutual positions on the other. The procedure derived can be used for computer simulation of curves representing the decrease of the activity of enzyme during its chemical modification or for the nonlinear regression analysis of such curves.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Analysis of essential amino acid residues for catalytic activity of cis-epoxysuccinate hydrolase from Bordetella sp. BK-52

2013 ◽  
Vol 98 (4) ◽  
pp. 1641-1649 ◽  
Author(s):  
Wenna Bao ◽  
Haifeng Pan ◽  
Zhenhong Zhang ◽  
Yongqing Cheng ◽  
Zhipeng Xie ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Amino Acid Residues
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