Isolation of a Thiamine-binding Protein from Rice Germ and Distribution of Similar Proteins.
A thiamine-binding protein was purified from rice germ (Oryza sativa L.) by extraction, salting-out with ammonium sulfate, and column chromatography. From the results of molecular mass, Kd and Bmax values for thiamine-binding, binding specificity for thiamine phosphates and analog, the protein was suggested to be identical to the thiamine-binding protein in rice bran. The thiamine-binding protein w as more efficiently purified from rice germ than from rice bran. The protein was rich in glutamic acid (and/or glutamine) and glycine. The protein did not show immunological similarity to thiamine-binding proteins in buckwheat and sesame seeds. However proteins similar to the thiamine-binding protein from rice germ existed in gramineous seeds. They were suggested to have thiamine-binding activity and to be of the same molecular mass as the thiamine-binding protein.
a Department of Food and Nutrition, Faculty of Agriculture , Kinki University, Nakamachi , Nara 631 , Japan.
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Shimizu
a Department of Food and Nutrition, Faculty of Agriculture , Kinki University, Nakamachi , Nara 631 , Japan.
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Yoshida
a Department of Food and Nutrition, Faculty of Agriculture , Kinki University, Nakamachi , Nara 631 , Japan.|b School of Medicine, University of the Ryukyus, Nakagusuku , Okinawa 903-01 , Japan.
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Toda
a Department of Food and Nutrition, Faculty of Agriculture , Kinki University, Nakamachi , Nara 631 , Japan.|c Department of Biochemistry , Kyoto Prefectural University of Medicine , Kamigyo-ku, Kyoto 602 , Japan.
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Iwashima
a Department of Food and Nutrition, Faculty of Agriculture , Kinki University, Nakamachi , Nara 631 , Japan.
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Mitsunaga
gramineous seeds; rice germ; thiamine; thiamine-binding protein