Oxidation of Arg-410 promotes the elimination of human serum albumin

The effect of the oxidation of amino acid residues on albumin on its in vivo elimination was investigated using mutants and oxidized HSAs. The single-residue mutants (H146A, K199A, W214A, R218H, R410A, Y411A) and oxidized HSAs were produced by the recombinant DNA techniques and incubation with a metal ion-catalyzed oxidation (MCO) system for 12, 24, 48 or 72 h. Pharmacokinetics were evaluated in mice after labeling with In-111. Structural and functional properties were examined by several spectroscopic techniques. Time-dependent increase in carbonyl group content resulted in increase in the liver clearance of oxidized HSAs. Slight decreases in a-helical content as the result of oxidation was induced by the increases in accessible hydrophobic areas and the net negative charge on the HSA molecule. No significant change in the pharmacokinetics and structural properties was observed for the W214A, R218H and Y411A mutants, but the properties for the H146A, K199A and R410A mutants were affected (extent of effect: R410A > K199A > H146A). The liver clearance of these proteins is closely correlated to hydrophobicity (r=0.929 P < 0.01) and the net charge of the proteins (r=0.930, P < 0.01). The rate of elimination of HSA is closely related to the hydrophobicity and net charge of the molecule. Further, the R410A mutants had a short half-life and structure similar to oxidized HSA after oxidation. Therefore, the modification of Arg-410 via oxidative stress may promote the elimination of HSA. (c) 2006 Elsevier B.V. All rights reserved.

利用突变体和氧化的人血清白蛋白（HSAs）研究了白蛋白上氨基酸残基氧化对其体内清除的影响。通过重组DNA技术以及在金属离子催化氧化（MCO）系统中分别孵育12、24、48或72小时，制备了单残基突变体（H146A、K199A、W214A、R218H、R410A、Y411A）和氧化的HSAs。用铟 - 111标记后在小鼠体内评估药代动力学。通过几种光谱技术检测结构和功能特性。羰基含量随时间增加导致氧化的HSAs在肝脏中的清除率增加。由于可及疏水区域增加以及HSA分子上净负电荷增加，氧化导致α - 螺旋含量略有下降。W214A、R218H和Y411A突变体的药代动力学和结构特性未观察到显著变化，但H146A、K199A和R410A突变体的特性受到影响（影响程度：R410A > K199A > H146A）。这些蛋白质在肝脏中的清除率与疏水性（r = 0.929，P < 0.01）和蛋白质的净电荷（r = 0.930，P < 0.01）密切相关。HSA的清除速率与分子的疏水性和净电荷密切相关。此外，R410A突变体在氧化后具有较短的半衰期和与氧化的HSA相似的结构。因此，通过氧化应激对精氨酸 - 410的修饰可能促进HSA的清除。（c）2006 Elsevier B.V. 保留所有权利。