【摘要】 光敏化剂竹红菌甲素在可见光区有三个吸收峰,其波长为475nm、545nm和585nm。在有竹红菌甲素存在时,红细胞膜样品用250W碘钨灯照射,其光强度为48尔格/平方毫米·秒。辐照后观察到以下一些效应:1)膜蛋白SH基含量减少。2)膜蛋白敏感的氨基酸残基,如组氨酸、半胱氨酸和色氨酸含量降低。3)膜蛋白发生光??聚集作用。4)多聚不饱和类脂发生过氧化作用。竹红菌甲素光照不同时间后和竹红菌甲素光照后放置一段时间,再加到红细胞膜中,均能观察到膜蛋白SH基含量降低。提示竹红菌甲素的光氧化产物是稳定的,能引起红细胞膜的光损伤。更多还原

【Abstract】 The photosensitizer hypocrellin A(H_A) was isolated from a kind of fungusHypocrella bambusae sacc.It is a pery-loquinone derivative with 3 absorptionbands in the visible region at 475 nm.545 nm and 585 nm (Fig.1). Samples of erythrocyte membraneswere irradiated with 250W tungstenlamp (Light intensity:48ergs/mm~2.sec) in the presence of H_A.The follow-ing effects were observed after irradia-tion:(a) diminution in membrane pro-tein SH content (Fig.2),(b) decreasein sensitive amino acid residues,such ashistidine,cysteine and tryptophan(Table 1),(c) photoaggregation ofmembrane proteins (Fig 3) and (d)peroxidation of polyunsaturated lipids(Fig 4).Hence H_A is an effective pho-tosensitizer. Membtanes (2.0mg of protein/ml) were irra-diated for 10 min and 60 min,in the presence of0.1 mM hypocrellin A.Determined according toEllman in membranes solubilized with 1% SDS.Trp was determined according to Spies. H_A itself was irradiated for variousintervals of time,then added to ery-throcyte membranes and allowed tostand for some time.In all cases adecrease in SH content was observed.This suggests that the photooxidationproducts of H_A are stable and cause da-mage in erythrocyte membranes.更多还原