新型荧光环肽探针用于病变胶原蛋白的靶向检测

Specific recognition of denatured collagen by novel fluorescent cyclic peptide probe

胶原蛋白是细胞外基质的主要成分,它在细胞分化、迁移、组织重塑和器官形态发生等大量生理过程中发挥着重要作用.作为关键的结构蛋白,胶原蛋白的过度降解与肿瘤等严重疾病的发生息息相关,已成为癌症分化、侵袭、转移以及癌症分期的重要诊断标准.因此,构建胶原蛋白的高效检测方法对肿瘤等相关疾病分子机制的解析和治疗方法的开发至关重要.环肽具有较为刚性的结构、高的酶稳定性和良好的药理特性等优点.本文利用邻苯二甲醛(OPA)与多肽序列中的赖氨酸和半胱氨酸反应,在(Gly-Pro-Hyp)n序列的基础上进行环化修饰,成功合成了一个环肽探针FAM-c CTP.组织染色的结果表明, FAM-c CTP不需要任何预处理,即可靶向识别小鼠和人的多种石蜡组织切片中的变性胶原.与特异性结合某种特定类型的胶原蛋白抗体相比, FAM-c CTP是广谱型探针,可用于选择性检测不同类型和不同物种来源的变性胶原蛋白.该环肽探针可以一直保持单链状态,不需要加热等预处理,克服了传统(Gly-Pro-Hyp)n探针的缺陷,为病变胶原蛋白的靶向检测和病理组织染色提供了新的工具.

As the principal component of the extracellular matrix, collagen plays an important role in various physiological processes such as cell differentiation and migration, tissue remodeling and organ morphogenesis. As a key structural protein, excessive degradation of collagen leads to severe diseases such as tumors, and it has been established as a key prognostic factor for cancer differentiation, invasion and metastasis as well as cancer stage. Therefore, the development of robust assays for collagen is crucial for the diagnosis and therapeutics for various collagen-involved diseases such as tumors. Cyclic peptides have attractive features such as more rigid structure, higher enzymatic stability and excellent pharmacological properties. We have utilized the phthalaldehyde(OPA) reaction of lysine and cysteine to achieve the cyclization of the(Gly-Pro-Hyp)nsequence, and created a cyclic peptide probe FAM-cCTP. The cyclic peptide probe has been shown to always maintain the single stranded state, and display high specificity of pathological collagen. Furthermore, it has been successfully applied for imaging studies of a broad variety of mice and human tissues.The peptide probe synthesized by the cyclization strategy does not need the heating pretreatment, and has overcome the defects of the traditional(Gly-Pro-Hyp)nprobe. It provides a novel tool for specific detection of pathological collagen and effective staining of pathological tissues.