Liu Lei, Breslow Ronald
Department of Chemistry, Columbia University, New York, New York 10027, USA.
J Am Chem Soc. 2003 Oct 8;125(40):12110-1. doi: 10.1021/ja0374473.
PAMAM dendrimers from generations 1-6 were synthesized with pyridoxamine in their core. They transaminated pyruvic and phenylpyruvic acids in water to alanine and phenylalanine, respectively, with Michaelis-Menten kinetics and high effectiveness compared with simple pyridoxamine. The largest dendrimers-similar in size to some globular proteins-were comparable in effectiveness to a previous polyethylenimine (PEI)-pyridoxamine catalyst, and to a protein-pyridoxamine catalyst, but not as effective as a previous PEI-pyridoxamine carrying lauryl hydrophobic groups. The new catalysts showed both general acid/base catalysis by their amino groups and hydrophobic binding of the phenylpyruvate substrate.
第1代至第6代的聚酰胺-胺（PAMAM）树枝状大分子在其核心部位与吡哆胺合成。它们在水中将丙酮酸和苯丙酮酸分别转氨生成丙氨酸和苯丙氨酸，具有米氏动力学，与单纯的吡哆胺相比效率较高。最大的树枝状大分子——大小与一些球状蛋白质相似——在效率上与之前的聚乙烯亚胺（PEI）-吡哆胺催化剂以及蛋白质-吡哆胺催化剂相当，但不如之前带有月桂基疏水基团的PEI-吡哆胺有效。新催化剂通过其氨基显示出一般酸碱催化作用，并对苯丙酮酸底物具有疏水结合作用。
