Adachi O, Okamoto K, Shinagawa E, Matsushita K, Ameyama M
Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Japan.
Biofactors. 1988 Oct;1(3):251-4.
When pyrroloquinoline quinone (PQQ) is mixed with an amino acid, a corresponding Schiff base PQQ adduct is readily formed between carbonyl groups of PQQ and the primary amino group. A potent growth stimulating effect for microorganisms was observed with the PQQ adduct when it was administered in a culture medium. Although PQQ itself shows a marked growth stimulating effect, PQQ adducts appeared to be more active than authentic PQQ when compared on a molar basis. Conversely, unlike authentic PQQ, PQQ adducts were shown to be less active (greater than or equal to 100-fold) as the prosthetic group for a quinoprotein apo-glucose dehydrogenase when examined by holoenzyme formation by exogenous addition of PQQ or PQQ adducts. These observations suggested that PQQ adduct formation readily occurs during isolation procedures for PQQ from biological materials or PQQ - chromophore from quinoproteins. Therefore, the presence of such adducts gives a PQQ estimation much lower than theoretically expected. As an example, formation, isolation and characterization of PQQ - serine are described.
当吡咯喹啉醌（PQQ）与氨基酸混合时，PQQ的羰基与伯氨基之间很容易形成相应的席夫碱PQQ加合物。当PQQ加合物添加到培养基中时，观察到其对微生物有显著的生长刺激作用。尽管PQQ本身就具有明显的生长刺激作用，但以摩尔为基础比较时，PQQ加合物似乎比纯PQQ更具活性。相反，与纯PQQ不同，当通过外源添加PQQ或PQQ加合物形成全酶来检测时，PQQ加合物作为醌蛋白脱辅基葡萄糖脱氢酶的辅基，其活性较低（大于或等于100倍）。这些观察结果表明，在从生物材料中分离PQQ或从醌蛋白中分离PQQ - 发色团的过程中，很容易形成PQQ加合物。因此，这些加合物的存在使得PQQ的估计值远低于理论预期值。例如，本文描述了PQQ - 丝氨酸的形成、分离和表征。
