Peptide bonds Periodic Table

The bond highlighted m yellow is the peptide bond ) Pencyclic reaction (Section 10 12) A reaction that proceeds through a cyclic transition state Period (Section 1 1) A honzontal row of the penodic table Peroxide (Section 6 8) A compound of the type ROOR Peroxide effect (Section 6 8) Reversal of regioselectivity oh served m the addition of hydrogen bromide to alkenes brought about by the presence of peroxides m the reaction mixture... 

Table VII summarizes the conditions for chymotryptic hydrolysis of the proteins and peptides listed in Table VI. The parameters which would be expected to determine the rate of hydrolysis (apart from the nature of the bonds in the particular substrates) are temperature, pH, time of hydrolysis, and the molar ratio of chymotrypsin to substrate. All these factors often differ considerably for the substrates listed. Hydrolyses have been performed under conditions which vary from 2 to 24 hr, from pH 7.0 to 9.0, from 22° to 40°C, and at enzyme to substrate molar ratios between 1/360 to 1/21. It is not obvious how variations in pH and temperature affect the apparent specificity of chymotrypsin, but at low molar ratios of enzyme to substrate only the most susceptible bonds would be expected to be hydrolyzed. The lowest molar ratio was employed in the studies with ribonuclease. The only bonds of an unusual nature which were split were those formed by serine and histidine in the following sequences, -Thr-Ser. . . Ala-Ala- and -Lys-His. . . Ileu-Ileu-. Many of the unusual splits listed in Table VI were observed in equine or human cytochrome c and in oxidized papain. Each of these substrates was digested for long periods of time and at high ratios of enzyme to substrate under conditions which would be expected to split bonds that are usually resistant to hydrolysis.

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