NEW CLASSES OF INHIBITORS OF HBS GELATION

描述 (改编自申请人的摘要)调查人员请求支持 努力寻找抑制镰刀凝胶化的新型配体 细胞血红蛋白(HBS)。他们已经开始了这个项目的工作，没有 外部资金。他们计划的第一步依赖于初步的 用分子筛选法筛选已知小分子结构文库 计算方法。程序对接利用硬脂酸互补 作为判断所选配体是否可与特定配体结合的标准 蛋白质表面上的位置。而不是瞄准测试版85-88 申请者所拥有的突变Val-beta6残基占据的结合位点 选择通过以下方式尝试破坏HBS光纤内的轴向接触 将配体定向到Glu-121附近，Glu-121直接位于 HBS光纤单丝内的分子间界面。步骤 二是对配体进行更详细的、基于能量的计算 由Dock建议。研究人员提出了三项实验测试 配基穿过它们的计算屏幕。第一，开展一项 小HBS样品的常规抗凝胶法。第二，衡量 配基是否与HBS有可测量的结合。后一步是 有必要避免拒绝太小的潜在有用的化合物 或者结合太弱，在抗凝胶化试验中看不到。第三，到 结晶并确定任何潜在有用的络合物的结构 那张表格。 申请者使用Dock筛选了剑桥大学的Small数据库 分子晶体结构，包含约90,000个条目。他们还拥有 对以下建议的优秀候选人进行了广泛的基于能量的计算 并开发了一份约100种化合物的清单供尝试。调查人员正在 开始对其中的一个子集进行抗凝胶化测试。 所请求的支持将提供以下功能： 对包括可用和临床价值的数据库的计算 化合物；购买额外的相关软件，以及更多的试验 超出申请者所能负担的范围；支持 开发HBS结合分析；并使拟议的 结晶学研究

DESCRIPTION (Adapted from applicant's abstract) The investigators request support for an effort to find new classes of ligands that inhibit the gelation of sickle cell hemoglobin (HbS). They have already begun work on this project without external funding. The first step in their scheme relies on the preliminary screening of a library of known small molecule structures using a computational approach. The program DOCK utilizes stearic complementarity as a criterion to decide whether a chosen ligand might bind to a specific site on the surface of a protein. Instead of targeting the beta 85-88 binding site occupied by the mutant val-beta6 residue the applicants have chosen to try to disrupt the axial contacts within the HbS fiber by directing ligands to the vicinity of Glu-121, which lies directly in the inter-molecular interface within a single filament of the HbS fiber. Step two carries out more detailed, energy-based calculations on ligands suggested by DOCK. The investigators propose three experimental tests of ligands passing through their computational screen. First, to carry out a conventional anti-gelation assay on small HbS samples. Second, to measure whether the ligand has measurable binding to HbS. The latter step is necessary to avoid rejecting potentially useful compounds that are too small or too weakly binding to be seen in the anti-gelation assay. Third, to crystallize and determine the structures of any potentially useful complexes that form. Using DOCK the applicants have screened the Cambridge database of small molecule crystal structures, which contains ~90,000 entries. They have also done extensive energy-based computations on good candidates suggested by DOCK, and developed a list of about 100 compounds to try. Investigators are beginning anti-gelation assays on a subset of these. The requested support will provide the ability to: extend these calculations to databases comprising available and clinically valuable compounds; to purchase additional relevant software, and many more trial compounds than the applicants have been about to afford; to support development of the HbS binding assay; and to enable the proposed crystallographic studies.