Jelsch C, Longhi S, Cambillau C
Architecture et Fonction des Macromolécules Biologiques, AFMB-CNRS, Marseille, France.
Proteins. 1998 May 15;31(3):320-33.
During the characterization of mutants and covalently inhibited complexes of Fusarium solani cutinase, nine different crystal forms have been obtained so far. Protein mutants with a different surface charge distribution form new intermolecular salt bridges or long-range electrostatic interactions that are accompanied by a change in the crystal packing. The whole protein surface is involved in the packing contacts and the hydrophobicities of the protein surfaces in mutual contact turned out to be noncorrelated, which indicates that the packing interactions are nonspecific. In the case of the hydrophobic variants, the packing contacts showed some specificity, as the protein in the crystal tends to form either crystallographic or noncrystallographic dimers, which shield the hydrophobic surface from the solvent. The likelihood of surface atoms to be involved in a crystal contact is the same for both polar and nonpolar atoms. However, when taking areas in the 200-600 A2 range, instead of individual atoms, the either highly hydrophobic or highly polar surface regions were found to have an increased probability of establishing crystal lattice contacts. The protein surface surrounding the active-site crevice of cutinase constitutes a large hydrophobic area that is involved in packing contacts in all the various crystalline contexts.
在对茄腐镰刀菌角质酶的突变体和共价抑制复合物进行表征的过程中，到目前为止已获得了九种不同的晶体形式。具有不同表面电荷分布的蛋白质突变体形成了新的分子间盐桥或长程静电相互作用，同时伴随着晶体堆积的变化。整个蛋白质表面都参与了堆积接触，并且相互接触的蛋白质表面的疏水性被证明是不相关的，这表明堆积相互作用是非特异性的。在疏水变体的情况下，堆积接触表现出一定的特异性，因为晶体中的蛋白质倾向于形成晶体学或非晶体学二聚体，从而使疏水表面与溶剂隔离。极性和非极性原子参与晶体接触的可能性相同。然而，当考虑200 - 600 Ų范围内的区域而非单个原子时，发现高度疏水或高度极性的表面区域建立晶格接触的概率增加。角质酶活性位点裂隙周围的蛋白质表面构成了一个大的疏水区域，在所有不同的晶体环境中都参与堆积接触。
