Structural Biochemistry/Vaclaw L. Kretovich

Vaclaw Leonovich Kretovich- member of the Russian Science Academic was born on January 27, 1907 in Yalta, Russia. He was one of the pioneers in biochemistry research. Throughout his life, he had discovered and contributed many important fields in biochemistry.

Introduction
He was raised in the family that did business in wine-making. During his college, he worked as a laboratory assistant and as a chemist at the same time. He started his biochemistry career at the age of 24 after graduating from Moscow State University in 1931. His career started when he was selected to work in the Protein and Protein Exchange Research with the Lenin All-Union Academy of Agricultural Sciences at that moment. After this, he spent most of his life time working at the Institute of Biochemistry. He became a professor and started teaching and doing research in biochemistry. There were hundreds of students under his guidance succeeded in obtaining doctor of science and many of them are holding important positions in biochemistry field. Upon completion of all degrees, in 1962, he became a member of USSR Academy of Sciences with a hope in finding out the connection between: biochemistry of bread and grain, and the biochemistry of nitrogen fixation and nitrogen metabolism. This was his biggest contribution to the biochemistry field. . One can easily find out about all of his work by the book Nitrogen Assimilation and Metabolism in Plants. This book about him and his work has been the best book in biochemistry.

The biochemistry of nitrogen fixation and nitrogen metabolism
He began the study of enzymatic complex of nitrogenase. After a series of studies, he and his coworkers found out about the role of molybdenum which played an important function in nitrogenase and nitro reductase. With this success, he came closer to the different point between the two most important enzymes of nitrogen-fixing microorganisms and nitrogen metabolisms. The ratios of these two enzymes depended mostly on the nitrogen source and they always competed with each other for molybdenum.

In his group, he worked with many other biochemists. Together with Z.G.Evstigneeva, they figured out the study of glutamine synthetase and glutamate dehydrogenase. He also worked with T.LAuerman to learn about the properties of glutamine synthetase and glutamate dehydrogenase in yeasts. He also studied the rold of hemoproteins in nitrogen fixation. There were many researches in leghemoblogin which was a myoglobin-like protein that led to the difference between nitrogen fixation and leghemoglobin; synthesis of leghemoglobin was impaired to a greater degree than other hemoproteins.

Kretovich and his teamwork research discovered a new enzyme which was metleghemoglobin reductase. This enzyme mainly functioned in reducing leghemoblogin and keeping physiological state. After a series of studies, they found out that this enzyme was not in nodulin even it belonged to plant origin. This discovery led the world to have a better understanding in metleghemoglobin.

He and his teamwork also researched in amino acid synthesis of lysine, valine, tryptophan, isoleucine in plants. This research pointed out some important keys:
 * For lysine synthesis, it starts via diaminopimelic acid in plant, but it starts via aminoadipic acid in fungi.
 * For valine and isoleucine synthesis, the keto and dioxy analogs became corresponding amino acids.
 * For tryptophan synthesis, it starts via anthranilic acid and indole.

Biochemistry of Grain and Bread
Another emphasis that Kretovich did was to study the biochemistry of grain and bread. His work led to the discovery of factors that determining the grain respiration intensity. It also let us know how biochemical functions in the storage of grain and bread. There was a disease called septic angina that happened in some parts of Russia. By mastering biochemistry of grain and bread, Kretovich and his coworker figured out that this disease was caused by the grain that was covered under the snow. This toxic grain was under studied and the technique to cure this disease was developed. Kretovich also focused on the kinetic biochemistry of bread. By using the enzymatic preparation that was isolated from microbial cultures, he came up with a proposal to increase the quality of the bread.

Reference
Applied Biochemistry and Microbiology, 2007, Vol. 43, No. 3, pp. 233–236. © Pleiades Publishing, Inc, 2007