Tito Ureta
From Wikipedia, the free encyclopedia
Tito Ureta | |
|---|---|
 | |
| Born | Tito Ureta Aravena 10 October 1935 |
| Died | June 9, 2012 (aged 76) |
| Education | University of Chile |
| Scientific career | |
| Fields | Hexokinases, protein evolution |
| Institutions | University of Chile, Rockefeller University, New York |
| Thesis | Formas moleculares multiples de ATP-D-hexosa 6-fosfotransferasa (1982) |
| Academic advisors | Hermann Niemeyer, Fritz Albert Lipmann |
Tito Ureta Aravena (1935–2012) was a Chilean biochemist, known for studies of hexokinases in many organisms.
Tito Ureta was born on 10 October 1935 in Iquique, Chile, where he was educated at the Domingo Santa María School, and in the Liceo José Victorino Lastarria (Santiago).[1] He married Sara Elfriede Herbstaedt Yáñez.[2]
Education and early research
Ureta's first university studies at the University of Chile were in medicine, and he qualified as a surgeon in 1963.[1] However, his interest turned to biochemistry and he devoted his career to research and experimental work, on hexokinases in particular.
In 1960 he joined the group of Hermann Niemeyer, with whom he obtained his doctorate on the basis of a thesis on the purification and characterization of the enzyme responsible for phosphorylation of glucose in the mammalian liver.[3][4]
He completed his training in a post-doctoral period in the laboratory of Fritz Lipmann at the Rockefeller University in New York.[1][5]
Research career
Ureta devoted much of his career to the study of hexokinases, mainly in mammals, but also in many other organisms, such as birds,[6] amphibians,[7] other vertebrates,[8] and fungi.[9][10]
Ureta and colleagues determined that there were four isoenzymes of hexokinase in rat liver, and proposed the sequence A, B, C, D on the basis of the order of elution from chromatographic columns of DEAE cellulose.[11] A little later Katzen and colleagues observed the same order for starch-gel electrophoresis and designated the isoenzymes as I, II, III and IV,[12] a terminology that has been widely adopted, for example by Agius and colleagues.[13]
Hexokinase A (or I), predominant in brain,[14] hexokinase B (or II), predominant in muscle,[15] and hexokinase D (or IV), predominant in liver hexokinase (or “glucokinase”),[16] have been extensively studied, but hexokinase C (or III) has received rather little attention, and Ureta is one of the few who have studied its properties.[7][17]
His study of the hexokinase isoenzymes in the rat led to a more general interest in the role of isoenzymes in metabolism.[18][19] His comparison of hexokinases from a wide variety of sources[20] stimulated a detailed study of the evolution of their structures.[21]
His interest was later devoted to the study of metabolic regulation in vivo, especially in relation to glycolysis,[22] the pentose phosphate pathway[23] and glycogen synthesis.[24] For these studies he used frog oocytes as a convenient tool, and he advocated their wide use.[25][26]
