目前,X射线晶体学,通常使用同步加速器源,仍然是蛋白质和其他生物分子结构确定的主要方法。然而,小的蛋白质晶体不能提供足够高分辨率的衍射图,并遭受辐射损伤;因此,传统的X射线晶体学需要更大的蛋白质晶体。使用X射线自由电子激光器(XFELs)的串行晶体学的新兴方法避免了这些挑战:它提供了来自弱衍射物体的出色结构数据,包括微小的晶体.XFEL是通过用非常强的X射线束照射微晶悬浮液的微射流来实现的。然而,虽然创建微晶微射流的方法已经建立,很少注意适合XFEL实验的高质量纳米/微晶的生长。在这项研究中,为了帮助这种晶体的生长,我们计算了平均晶体尺寸和在分批结晶中将晶体生长到所需尺寸所需的时间(制备所需微晶浆料的主要方法);从理论上讲,对于微晶和大于Gibbs-Thomson效应上限的晶体,都可以计算这个时间。还定量地考虑了无所不在的杂质对微晶生长的影响。实验,用模型蛋白溶菌酶进行,支持理论预测。
Currently, X-ray crystallography, which typically uses synchrotron sources, remains the dominant method for structural determination of proteins and other biomolecules. However, small protein crystals do not provide sufficiently high-resolution diffraction patterns and suffer radiation damage; therefore, conventional X-ray crystallography needs larger protein crystals. The burgeoning method of serial crystallography using X-ray free-electron lasers (XFELs) avoids these challenges: it affords excellent structural data from weakly diffracting objects, including tiny crystals. An XFEL is implemented by irradiating microjets of suspensions of
microcrystals with very intense X-ray beams. However, while the method for creating microcrystalline microjets is well established, little attention is given to the growth of high-quality nano/
microcrystals suitable for XFEL experiments. In this study, in order to assist the growth of such crystals, we calculate the mean crystal size and the time needed to grow crystals to the desired size in batch crystallization (the predominant method for preparing the required microcrystalline slurries); this time is reckoned theoretically both for
microcrystals and for crystals larger than the upper limit of the Gibbs-Thomson effect. The impact of the omnipresent impurities on the growth of
microcrystals is also considered quantitatively. Experiments, performed with the model protein lysozyme, support the theoretical predictions.