膜蛋白是生物领域研究中的热点和难点。在光合作用研究中,对于藻类个体发育过程中光合膜蛋白结构和功能的变化所知甚少,其中的一个限制因素是能否纯化得到大量高活性的稳定且均一的光合膜蛋白。作者从条斑紫菜(Porphyra yezoensis)孢子体和配子体中分离纯化得到光合系统(PSⅡ)复合物,并研究了其完整性和放氧活性。结果表明,孢子体和配子体的PSⅡ复合物,在4℃条件下保存比在-80℃下保存放氧活性高,稳定性高。配子体PSⅡ复合物,在-80℃保存第6天就已经没有放氧活性,而孢子体PSⅡ复合物仍有放氧活性。对4℃下保存的PSII复合物进行分子筛柱层析,室温吸收光谱测定以及放氧活性测定,发现随着放氧活性逐渐降低,蛋白大分子有聚合现象。室温吸收光谱表明经过长期的保存,吸收峰向短波长方向偏移,叶绿素易降解成为脱镁叶绿素 Membrane protein is a hot and difficult area in biological research. In photosynthesis research, little is known about the changes in the structure and function of photosynthetic membrane proteins during the development of algae. One of the limiting factors is whether a large number of highly active and stable photosynthetic membrane proteins can be purified. The authors isolated and purified photosynthetic system (PSII) complexes from Porphyra yezoensis sporophytes and gametophytes, and studied their integrity and oxygen evolution activity. The results showed that the PSⅡ complex of sporophyte and gametophyte had higher activity and stability at 4 ℃ than oxygen stored at -80 ℃. Gametophyte PSⅡ complex, no activity of oxygen release at -80 ℃ for 6 days, while the sporophyte PSⅡ complex still has oxygen-releasing activity. The PSII complex stored at 4 ℃ was subjected to molecular sieve column chromatography, absorption spectrum at room temperature and oxygen activity determination. It was found that the protein macromolecules were polymerized with the gradual decrease of oxygen evolution activity. Absorption spectrum at room temperature shows that after long-term storage, the absorption peak shifts to the short wavelength and the chlorophyll is easily degraded into pheophytin