2.6.1.29 pyridoxal 5'-phosphate - 759319 2.6.1.29 pyridoxal 5'-phosphate PLP 759321 2.6.1.29 pyridoxal 5'-phosphate purified enzyme normally active without added pyridoxal phosphate, absolute requirement when irradiated with UV light or treated with 2 mM phenylhydrazine and then with Norite 639951 2.6.1.29 pyridoxal 5'-phosphate required 639950