Strong R K, Bratt T, Cowland J B, Borregaard N, Wiberg F C, Ewald A J
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
Acta Crystallogr D Biol Crystallogr. 1998 Jan 1;54(Pt 1):93-5. doi: 10.1107/s0907444997010615.
Crystals of the monomeric and dimeric forms of human neutrophil gelatinase associated lipocalin have been grown in hanging-drop vapor-diffusion trials using PEG as a precipitating agent with recombinant protein expressed in a baculovirus-based system. Crystals of monomeric NGAL belong to the cubic space group P432 with lattice constants a = b = c = 126.6 A; crystals of dimeric NGAL belong to the tetragonal space group P41212 (or its enantiomorph P43212) with lattice constants a = b = 54.14 and c = 121.56 A. Isomorphous crystals of the NGAL dimer can be grown in the presence of ligand: the tripeptide N-formyl-Met-Leu-Phe.
利用聚乙二醇（PEG）作为沉淀剂，通过悬滴气相扩散试验，培养了基于杆状病毒系统表达的重组蛋白的人中性粒细胞明胶酶相关脂质运载蛋白单体和二聚体形式的晶体。单体NGAL晶体属于立方空间群P432，晶格常数a = b = c = 126.6 Å；二聚体NGAL晶体属于四方空间群P41212（或其对映体P43212），晶格常数a = b = 54.14，c = 121.56 Å。在配体（三肽N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸）存在的情况下，可以培养出NGAL二聚体的同晶型晶体。
