Cook Alison F, Grover Phulwinder K, Ryall Rosemary L
Department of Surgery, Flinders University School of Medicine, Flinders Medical Centre, Bedford Park, South Australia, Australia.
BJU Int. 2009 Mar;103(6):826-35. doi: 10.1111/j.1464-410X.2008.08195.x. Epub 2008 Nov 13.
To compare the intracrystalline distributions of prothrombin fragment 1 (PTF1) and human serum albumin (HSA) within inorganic and urinary calcium oxalate (CaOx) monohydrate (COM) crystals and to determine whether binding of PTF1 can be explained by interactions between particular gamma-carboxyglutamic (Gla) residues and atomic arrays on individual faces of the COM crystal. MATERIALS AND METHODS COM: crystals were precipitated from inorganic solutions and ultrafiltered urine containing fluorescent HSA or PTF1 at different relative concentrations and examined by fluorescence microscopy. Accelrys Materials Studio and Discovery Studio were used to model the binding of PTF1 to the top, side and apical faces of the COM crystal.
PTF1 alone always adsorbed predominantly to the COM apical surfaces, while HSA bound principally to the side faces under inorganic conditions, but to the apical faces in urine. In the presence of each other, both proteins competed for adsorption to the apical faces, with attachment of PTF1 dominating over that of HSA. Modelling showed that urinary PTF1 had equal theoretical bonding potential for all three COM surfaces.
(i) Anisotropic inclusion of HSA and PTF1 into urinary and inorganic COM crystals results from their preferential binding to specific COM faces; (ii) the binding preference of HSA differs under inorganic and urinary conditions; (iii) preferential binding of PTF1 to the apical faces of COM is more complex than can be explained by interactions between Gla groups and surface atomic arrays; (iv) future studies of interactions between urinary proteins and stone mineral crystal surfaces should be performed in urine.
比较凝血酶原片段1(PTF1)和人血清白蛋白(HSA)在无机草酸钙(CaOx)一水合物(COM)晶体和尿草酸钙晶体中的晶内分布,并确定PTF1的结合是否可以通过特定γ-羧基谷氨酸(Gla)残基与COM晶体单个面的原子阵列之间的相互作用来解释。材料与方法:从含有不同相对浓度荧光HSA或PTF1的无机溶液和超滤尿液中沉淀COM晶体,并用荧光显微镜检查。使用Accelrys Materials Studio和Discovery Studio对PTF1与COM晶体的顶面、侧面和顶面的结合进行建模。
单独的PTF1总是主要吸附在COM晶体的顶面上,而HSA在无机条件下主要结合在侧面,但在尿液中结合在顶面上。在彼此存在的情况下,两种蛋白质竞争吸附到顶面上,PTF1的附着比HSA占优势。建模表明,尿PTF1对所有三个COM表面具有相同的理论结合潜力。
(i)HSA和PTF1在尿液和无机COM晶体中的各向异性包合是由于它们优先结合到特定的COM面上;(ii)HSA在无机和尿液条件下的结合偏好不同;(iii)PTF1优先结合到COM晶体顶面上的情况比Gla基团与表面原子阵列之间的相互作用所解释的更为复杂;(iv)未来关于尿蛋白与结石矿物晶体表面相互作用的研究应在尿液中进行。