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Lead–yeast hexokinase interaction: modifications to protein structure caused by the metal
Author(s) -
Teijón C,
Olmo R,
Socorro J M,
Blanco M D,
Romero A,
Teijón J M
Publication year - 2001
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.703
Subject(s) - yeast , chemistry , monomer , substrate (aquarium) , hexokinase , enzyme , active site , protein secondary structure , biophysics , protein quaternary structure , biochemistry , crystallography , biology , organic chemistry , polymer , glycolysis , protein subunit , gene , ecology
The interaction between lead and yeast hexokinase has been studied. Lead provokes a large variation in the aggregation state of the protein, forming bigger structures of high molecular mass. This phenomenon is characterized by a small modification in the tridimensional structure and a great variation in the secondary structure. There is a loss in α‐helix which is compensated by an enhancement in β‐sheet. The polypeptide chain is more stable in the β‐sheet structure corresponding to the aggregate forms. During this change the enzyme maintains a high level of activity in the monomer and also in the aggregate form. This implies that the enzyme function is not greatly affected by the change, and active sites are retained without important modifications. According to kinetic measurements the ATP site is more affected than the glucose site. There is a mixed type inhibition with a main competitive component when glucose acts as a variable substrate. © 2001 Society of Chemical Industry