we describe optimized , ultraviolet spectrophotometric procedures for determination of erythrocyte transketolase , glutathione reductase , and aspartate aminotransferase activity , and their activation by their respective coenzymes -- thiamine pyrophosphate , flavin-adenine dinucleotide , and pyridoxal-5-phosphate -- as tests for vitamin b1 , b2 , and b6 deficiency .
C0009235
coenzymes
C0039848
thiamine pyrophosphate