Borgstahl G E, Vahedi-Faridi A, Lovelace J, Bellamy H D, Snell E H
University of Toledo, Department of Chemistry, 2801 West Bancroft Street, Toledo, OH 43606, USA.
Acta Crystallogr D Biol Crystallogr. 2001 Aug;57(Pt 8):1204-7. doi: 10.1107/s0907444901007892. Epub 2001 Jul 23.
Crystals of insulin grown in microgravity on Space Shuttle Mission STS-95 were extremely well ordered and unusually large (many >2 mm). The physical characteristics of six microgravity and six earth-grown crystals were examined by X-ray analysis employing superfine phi slicing and unfocused synchrotron radiation. This experimental setup allowed hundreds of reflections to be precisely examined from each crystal in a short period of time. The microgravity crystals were on average 34 times larger, had sevenfold lower mosaicity, had 54-fold higher reflection peak heights and diffracted to significantly higher resolution than their earth-grown counterparts. A single mosaic domain model could account for the observed reflection profiles in microgravity crystals, whereas data from earth crystals required a model with multiple mosaic domains. This statistically significant and unbiased characterization indicates that the microgravity environment was useful for the improvement of crystal growth and the resultant diffraction quality in insulin crystals and may be similarly useful for macromolecular crystals in general.
在航天飞机任务 STS - 95 中于微重力环境下生长的胰岛素晶体排列极其有序且异常大（许多晶体大于 2 毫米）。通过使用超细 φ 切片和非聚焦同步辐射的 X 射线分析，对六颗微重力环境下生长的晶体和六颗地球重力环境下生长的晶体的物理特性进行了研究。这种实验装置使得在短时间内能够精确检测每颗晶体的数百次反射。微重力环境下生长的晶体平均尺寸大 34 倍，镶嵌性低七倍，反射峰高 54 倍，并且衍射分辨率比在地球重力环境下生长的对应晶体显著更高。单一镶嵌域模型可以解释微重力环境下生长的晶体中观察到的反射轮廓，而地球重力环境下生长的晶体的数据需要多个镶嵌域的模型。这种具有统计学意义且无偏差的表征表明，微重力环境有助于改善胰岛素晶体的晶体生长及由此产生的衍射质量，并且总体上可能对大分子晶体同样有用。
