Functional evaluation of tryptophanyl residues of bovine and porcine pancreatic deoxyribonucleases.
Trp-155 in bovine DNase A (EC 3.1.4.5) appeared to be unessential for the enzymatic activity for the following reasons: (1) A unique peptide which suggests the environmental difference of Trp-155 was obtained from porcine pancreatic DNase A. (2) Inactivation of the porcine DNase A by NBS modification was fairly paralleled with a decrease in the CD signal, which is characteristic of the "buried" tryptophan in the hydrophobic region (trp-191 in bovine DNase) but not of tryptophans in the hydrophilic portion. Binding of DNase to the poly I: poly C double helix confirmed the important role of this tryptophan.
Hashizume
H
H
Department of Chemistry, University of Shizuoka, Japan.
Shimomura
M
M
D000596:Amino Acids / Q000302:isolation & purification; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D003851:Deoxyribonucleases / Q000032:analysis* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010179:Pancreas / Q000201:enzymology*; D011070:Poly I-C / Q000378:metabolism; D013045:Species Specificity; D013552:Swine; D014364:Tryptophan / Q000032:analysis / Q000502:physiology*
D000596:Amino Acids; D014364:Tryptophan; D003851:Deoxyribonucleases; C019328:deoxyribonuclease A; D011070:Poly I-C