What question did this study set out to answer?

Determine whether the primary amino groups of bovine pancreatic deoxyribonuclease A are directly involved in catalytic cleavage or required for structural stability.

February 1, 1971Journal of Biological ChemistryOpen Access

Activity of Bovine Pancreatic Deoxyribonuclease A with Modified Amino Groups

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Authors

BPBryce V. PlappUniversity of Iowa SMStanford MooreRockefeller Foundation WSWilliam H. SteinRockefeller Foundation

Discussion

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Implication

Biochemical investigation reveals nonessential catalytic roles for primary amino groups in bovine pancreatic deoxyribonuclease A, indicating their primary function is maintaining structural stability.

Key Points

Determine whether the primary amino groups of bovine pancreatic deoxyribonuclease A are directly involved in catalytic cleavage or required for structural stability.
Modified bovine pancreatic DNase A using guanidination, picolinimidylation, carbamylation, and trinitrophenylation to alter primary α- and ε-amino groups.
Measured residual enzymatic activity of chemically modified derivatives in the presence and absence of calcium ions.
Quantified amino group modifications using chromatographic determination of homocitrulline and spectrophotometric titration with 2,4,6-trinitrobenzenesulfonic acid.
Guanidination of all nine ε-amino groups or picolinimidylation yielded active derivatives, showing that primary amino groups are not essential for catalytic activity.
Carbamylating the α-amino and seven ε-amino groups reduced activity to approximately 50%, which was nearly completely restored by calcium; carbamylating the final two amino groups caused irreversible inactivation.
Trinitrophenylation inactivated calcium-free DNase after modifying one amino group and calcium-bound DNase after modifying four to five groups, while two to three amino groups resisted modification.

Cite This Study

Plapp et al. (1971) studied this question.

synapsesocial.com/papers/6a8017ccda79b66310cab4bc https://doi.org/10.1016/s0021-9258(18)62414-7

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February 1, 1971Journal of Biological ChemistryOpen Access

Activity of Bovine Pancreatic Deoxyribonuclease A with Modified Amino Groups

View Full Paper

Ask AI

Bookmark

Authors

BPBryce V. PlappUniversity of Iowa SMStanford MooreRockefeller Foundation WSWilliam H. SteinRockefeller Foundation

Discussion

Member takes

Implication

Key Points

Determine whether the primary amino groups of bovine pancreatic deoxyribonuclease A are directly involved in catalytic cleavage or required for structural stability.
Modified bovine pancreatic DNase A using guanidination, picolinimidylation, carbamylation, and trinitrophenylation to alter primary α- and ε-amino groups.
Measured residual enzymatic activity of chemically modified derivatives in the presence and absence of calcium ions.
Quantified amino group modifications using chromatographic determination of homocitrulline and spectrophotometric titration with 2,4,6-trinitrobenzenesulfonic acid.
Guanidination of all nine ε-amino groups or picolinimidylation yielded active derivatives, showing that primary amino groups are not essential for catalytic activity.
Carbamylating the α-amino and seven ε-amino groups reduced activity to approximately 50%, which was nearly completely restored by calcium; carbamylating the final two amino groups caused irreversible inactivation.
Trinitrophenylation inactivated calcium-free DNase after modifying one amino group and calcium-bound DNase after modifying four to five groups, while two to three amino groups resisted modification.

Cite This Study

Plapp et al. (1971) studied this question.

synapsesocial.com/papers/6a8017ccda79b66310cab4bc https://doi.org/10.1016/s0021-9258(18)62414-7

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