Stepuro I I, Solodunov A A, Piletskaia T P, Iaroshevich N A, Ostrovskiĭ Iu M
Ukr Biokhim Zh (1978). 1988 Jan-Feb;60(1):34-41.
It is found that approximately 65-70% of pyridoxal-P at physiological concentrations is bound to plasma proteins; 15% of its amount is bound to amino acids and peptides as a result of the Schiff base formation. Over 85% of pyridoxal-P associated with plasma proteins is bound to serum albumin. Inorganic phosphate and NaCl decrease the affinity of pyridoxal-P for albumin or other proteins. Acetaldehyde interacts with the alpha-amino group of the aspartic acid residue of the N-end of the polypeptide chain of the albumin molecule and with two epsilon-amino groups of the lysine residues having anomalously low value of pKa and deprotonated at physiological values of pH of the medium. Acetaldehyde competes with pyridoxal-P for the first (of the highest affinity) binding site of the coenzyme on serum albumin. Acetaldehyde is not bound at the second site of high affinity for pyridoxal-P on serum albumin.
据发现，在生理浓度下，约65 - 70%的磷酸吡哆醛与血浆蛋白结合；由于席夫碱的形成，其15%的量与氨基酸和肽结合。与血浆蛋白结合的磷酸吡哆醛中，超过85%与血清白蛋白结合。无机磷酸盐和氯化钠会降低磷酸吡哆醛对白蛋白或其他蛋白质的亲和力。乙醛与白蛋白分子多肽链N端天冬氨酸残基的α - 氨基以及两个pKa值异常低且在介质生理pH值下已去质子化的赖氨酸残基的ε - 氨基相互作用。乙醛与磷酸吡哆醛竞争辅酶在血清白蛋白上的第一个（亲和力最高的）结合位点。乙醛不会结合在血清白蛋白上磷酸吡哆醛的第二个高亲和力位点。
