[Comparative study of the structural characteristics of aldolase in rabbit muscles in normal states and in alloxan diabetes].
It is shown that the activity of aldolase synthesized in rabbit muscles under diabetes is higher than that at normal state. This fact is probably a result of some structural alterations in NAD-binding site with Trp-291 and -311 in it which overlaps a considerable part of C-terminal region of the protein. The hydrophobic part of the enzyme containing Trp-147 under diabetes seems to remain unaltered. This consideration is based on the longwave shift in aldolase fluorescence lambda max (from 320 to 324 nm) under this pathology, suggesting a transition of Trp-291 and -311 into more polar environment and is confirmed by the disappearance of the difference in lambda max in the NADH presence. The NADH-originated shift in lambda max position for the both proteins ended at the same wave-length at 314 nm. The position of lambda max at 324 nm resulting from possible structural modification of NAD-binding site under diabetes correlates with an increase in the Stern-Volmer quenching constant value (from 4359 to 7500 M-1 for aldolase under normal and diabetic states, respectively). These quenching data evidence in favour of the suggestion on the existence of two classes of tryptophanyls in the aldolase molecule.
D000818:Animals; D001665:Binding Sites; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D005634:Fructose-Bisphosphate Aldolase / Q000032:analysis*; D009132:Muscles / Q000201:enzymology*; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000032:analysis
D014364:Tryptophan; D005634:Fructose-Bisphosphate Aldolase
Sravnitel'noe izuchenie strukturnykh osobennosteĭ al'dolazy myshts krolikov v norme i pri alloksanovom diabete.