As a ubiquitous enzyme, succinic semialdehyde dehydrogenase contributes significantly in many pathways including the tricarboxylic acid cycle and other metabolic processes such as detoxifying the accumulated succinic semialdehyde and surviving in nutrient-limiting conditions. Here the cce4228 gene encoding succinic semialdehyde dehydrogenase from Cyanothece sp. ATCC51142 was cloned and the homogenous recombinant cce4228 protein was obtained by Ni-NTA affinity chromatography. Biochemical characterization revealed that cce4228 protein displayed optimal activity at presence of metal ions in basic condition. Although the binding affinity of cce4228 protein with NAD⁺ was about 50-fold lower than that of cce4228 with NADP⁺, the catalytic efficiency of cce4228 protein towards succinic semialdehyde with saturated concentration of NADP⁺ is same as that with saturated concentration of NAD⁺ as its cofactors. Meanwhile, the catalytic activity of cce4228 was competitively inhibited by succinic semialdehyde substrate. Kinetic and structural analysis demonstrated that the conserved Cys262 and Glu228 residues were crucial for the catalytic activity of cce4228 protein and the Ser157 and Lys154 residues were determinants of cofactor preference.

琥珀酸半醛脱氢酶作为一种普遍存在的酶，在许多途径中都起着重要作用，包括三羧酸循环和其他代谢过程，例如将积累的琥珀酸半醛解毒并在营养限制条件下存活。在这里，编码ceanothece sp。的琥珀酸半醛脱氢酶的cce4228基因。克隆ATCC51142，并通过Ni-NTA亲和层析获得同质重组cce4228蛋白。生化特征表明，cce4228蛋白在碱性条件下在金属离子存在下显示出最佳活性。尽管cce4228蛋白与NAD ⁺的结合亲和力比cce4228与NADP ⁺的结合亲和力低约50倍。饱和浓度的NADP ^+时，cce4228蛋白对琥珀酸半醛的催化效率与饱和浓度的NAD ⁺作为辅因子时的催化效率相同。同时，琥珀酸半醛底物竞争性地抑制了cce4228的催化活性。动力学和结构分析表明，保守的Cys262和Glu228残基对于cce4228蛋白的催化活性至关重要，而Ser157和Lys154残基是辅因子偏爱的决定因素。