脂肪酸、烷基脲和尿素诱导高铁血红蛋白A、S和F形成半高铁血红蛋白。

Induced hemichrome formation of methemoglobins A, S and F by fatty acids, alkyl ureas and urea.

Harrington J P, Newton P, Crumpton T, Keaton L

Department of Chemistry and Comprehensive Sickle Cell Center, University of South Alabama, Mobile 36688.

Int J Biochem. 1993 May;25(5):665-70. doi: 10.1016/0020-711x(93)90351-e.

Abstract

Spectral analysis of the Soret region (450-350 nm) has shown that saturated fatty acids, alkyl ureas and urea induce the conversion of methemoglobins A, S, and F to the hemichrome state. 2. In the presence of fatty acids (C8-C16), methemoglobin F is converted to the hemichrome state more readily than either methemoglobins A or S. 3. Using several alkyl ureas (methyl, ethyl, propyl, butyl), the extent of hemichrome formation was as follows: met Hb F > met Hb S > met Hb A. The ability of these compounds to induce hemichrome formation is related to their increasing hydrophobicity. 4. Conversion to the hemichrome state in the presence of urea (5M) led to the formation of molecular aggregates of hemoglobins S, F and A which may be initiated by subunit dissociation and conformational changes, coupled to increased globin-globin interactions. 5. Similar aggregation occurred for methemoglobin S in the presence of octanoic acid; no significant aggregation was evident for methemoglobin A after 10 hr of exposure to octanoic acid.

摘要

对索雷特区域（450 - 350纳米）的光谱分析表明，饱和脂肪酸、烷基脲和尿素会促使高铁血红蛋白A、S和F转变为半色原状态。2. 在脂肪酸（C8 - C16）存在的情况下，高铁血红蛋白F比高铁血红蛋白A或S更容易转变为半色原状态。3. 使用几种烷基脲（甲基、乙基、丙基、丁基）时，半色原形成的程度如下：高铁血红蛋白F＞高铁血红蛋白S＞高铁血红蛋白A。这些化合物诱导半色原形成的能力与其疏水性增加有关。4. 在尿素（5M）存在的情况下转变为半色原状态会导致血红蛋白S、F和A形成分子聚集体，这可能由亚基解离和构象变化引发，并伴随着珠蛋白 - 珠蛋白相互作用的增加。5. 在辛酸存在的情况下，高铁血红蛋白S也会发生类似的聚集；高铁血红蛋白A在暴露于辛酸10小时后未出现明显的聚集现象。