期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：16
页码：9284-9289
DOI：10.1073/pnas.95.16.9284
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The crystal structure of triclinic lysozyme, comprised of 1,001 non-H protein atoms and {approx}200 bound water molecules, has been determined ab initio (using native data alone) by the "Shake-and-Bake" method by using the computer program SnB. This is the largest structure determined so far by the SnB program. Initial experiments, using default SnB parameters derived from studies of smaller molecules, were unsuccessful. In fact, such experiments produced electron density maps dominated by a single large peak. This problem was overcome by considering the choice of protocol used during the parameter-shift phase refinement. When each phase was subjected to a single shift of {+/-}157.5{degrees} during each SnB cycle, an unusually high percentage of random trials ({approx}22%) yielded correct solutions within 750 cycles. This success rate is higher than that typically observed, even for much smaller structures.
