Institut für Biologie, Zoologie - Molekulare Ökologie, Martin-Luther-Universität Halle-Wittenberg, Hoher Weg 4, 06120, Halle (Saale), Germany.
Facultatea de Zootehnie şi Biotehnologii, Universitatea de Ştiinţe Agricole şi Medicină Veterinară, Calea Mănăştur 3-5, 400372, Cluj-Napoca, Romania.
Sci Rep. 2019 Jun 21;9(1):9014. doi: 10.1038/s41598-019-45460-0.
Honey bee larval food jelly is a secretion of the hypopharyngeal and mandibular glands of young worker bees that take care of the growing brood in the hive. Food jelly is fed to all larvae (workers, drones and queens) and as royal jelly to the queen bee for her entire life. Up to 18% of the food jelly account for proteins the majority of which belongs to the major royal jelly protein (MRJP) family. These proteins are produced in the hypopharyngeal glands at a pH value of 7.0. Before being fed to the larvae, they are mixed with the fatty acids secreted by the mandibular glands of the worker bees resulting at a pH of 4.0 in the food jelly. Thus, MRJPs are exposed to a broad pH range from their site of synthesis to the actual secreted larval food. We therefore determined the pH-dependent stability of MRJP1, MRJP2 and MRJP3 purified from royal jelly using differential scanning fluorimetry. All MRJPs were much more stable at acidic pH values compared to neutral ones with all proteins showing highest stability at pH 4.0 or 4.5, the native pH of royal jelly.
蜂蜜蜂幼虫食品果冻是年轻工蜂的咽和下颌腺分泌的物质，用于照顾蜂巢中不断成长的幼虫。果冻状的食物被喂食给所有幼虫（工蜂、雄蜂和蜂王），并作为蜂王浆喂食给蜂王，供其一生食用。在食物果冻中，高达 18%的蛋白质属于蜂王浆蛋白（MRJP）家族。这些蛋白质在 pH 值为 7.0 的咽腺中产生。在被喂食给幼虫之前，它们与工蜂下颌腺分泌的脂肪酸混合，在食物果冻中形成 pH 值为 4.0。因此，MRJPs 在从合成部位到实际分泌的幼虫食物的过程中经历了广泛的 pH 范围。因此，我们使用差示扫描荧光法测定了从蜂王浆中纯化的 MRJP1、MRJP2 和 MRJP3 的 pH 依赖性稳定性。与中性 pH 值相比，所有 MRJPs 在酸性 pH 值下的稳定性都更高，所有蛋白质在 pH 值为 4.0 或 4.5（即蜂王浆的天然 pH 值）时稳定性最高。
