ANAEROBIC TOLUENE MINERALIZATION PATHWAY IN AZOARCUS TOLULYTICUS SP TOL 4

SIR提供了L-[4‘-’80]酪氨酸；Ig-Quinones代表了一种新的 翻译后形成的一类已发现的有机辅因子 芳香族氨基亚氨基酸的羟基化，从而使它们能够 在Tenzyme活性中心用作氧化还原催化剂。这个 三羟基苯丙氨酸辅因子(TPQ)存在于胺氧化酶(AO)中。 在那里它催化有机胺氧化成醛。这 反应由C5羰基上的胺攻击引发， 然后氧化成亚胺，然后释放一种 乙醛。还原的氨基喹酚辅因子被重新氧化成 涉及半醌的两个单电子步骤中的苯二酚 中级的。这种再氧化反应利用Cu2+作为直接的 电子受体R和末端电子受体02。共振 拉曼(RR)光谱已被证明是一种很好的技术 研究蛋白质中的苯醌辅因子。这些生色团产生 强烈增强的光谱，其振动模式对每个 辅因子类型；在我们对急性呼吸窘迫综合征中的TPQ辅因子的研究中 反应周期中，我们能够确定氧化状态 苯二酚和催化中间体的RR光谱分析。这些研究 通过使用同位素和一套广泛的人工合成的 为振动提供更坚实的结构基础的模型 任务。未来的研究方向将是阐明其发病机制。 生物合成，以提供有关催化的详细信息 反应性，并鉴定新的苯醌辅助因子的结构 在其他酶中。

The SIR provided L-[4'-'80]Tyrosine; Ig Quinones represent a newly discovered class of organic cofactors formed by postranslational hydroxylation of aromatic an-iino acids, thereby allowing them to servie as redox catalysts at tenzyme active sites. The trhydroxyphenylalanine cofactor, TPQ, is found in amine oxidases (AO) where it catlyzes the oxidation of organic amines to aldehydes. This reaction is initiated by amine attack at the C5 carbonyl group, followed by oxidation to an imine and subsequent release of an aldehyde. The reduced aminoquinol cofactor is reoxidezed to the quinone in two one- electron steps involving a semiquinone intermediate. This reoxidation reaction utilizes Cu2+ as an immediate electron acceptr and 02 as the terminal electron acceptor. Resonance Raman (RR) spectroscopy has proved to be an excellent technique for studying quinone cofactors in proteins. These chromophores produce strongly enhanced spectra whose vibrational pattern is unique for each type of cofactor;. In our study of the TPQ cofactor of AO during its reaction cycle we were able to identify oxidation states of the quinone and catalytic intermediates by RR spectroscoy. These studies were aided by the use of isotopes and an extensive set of synthetic models that provided a firmer structural basis for vibrational assignments. Future directions will be to elucidate the mechanissm of biosynthesis, to provide detailed information about catalytic reactivity, and to identify the structures of novel quinone cofactors in other enzymes.