Wei Wenyu, Li Dongfang, Cai Xiangdong, Liu Zhao, Bai Zhongtian, Xiao Jianxi
State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
The Second Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou 730000, Gansu Province, China.
ACS Omega. 2020 Dec 18;5(51):33075-33082. doi: 10.1021/acsomega.0c04684. eCollection 2020 Dec 29.
The construction of potent peptide probes for selectively detecting denatured collagen is crucial for a variety of widespread diseases. However, all of the denatured collagen-targeting peptide probes found till date primarily utilized the repetitive (Gly-X-Y) sequences with exclusively imino acids Pro and Hyp in the X and Y positions, which stabilized the triple helical conformation of the peptide probes, resulting in severe obstacles for their clinical applications. A novel series of peptide probes have been constructed by incorporating nonimino acids at the X position of the (GPO)GXO(GPO) sequence, while the X-site residue is varied as Tyr, Phe, Asp, and Ala, respectively. Peptide probes FAM-GYO and FAM-GFO containing aromatic residues Tyr and Phe at the X position showed similarly high binding affinity and tissue-staining efficacy as the well-established peptide probe FAM-GPO, while peptide probes FAM-GDO and FAM-GAO with the corresponding charged residue Asp and the hydrophobic residue Ala indicated much weaker binding affinity and tissue-staining capability. Furthermore, FAM-GYO and FAM-GFO could specifically detect denatured collagen in different types of mouse connective tissues and efficiently stain various human pathological tissues. We have revealed for the first time that the incorporation of nonimino acids, particularly aromatic residues at the X and Y positions of the repetitive (Gly-X-Y) sequences, may provide a convenient strategy to create novel robust collagen-targeting peptide probes, which have promising diagnostic applications in collagen-involved diseases.
构建用于选择性检测变性胶原蛋白的高效肽探针对于多种常见疾病至关重要。然而，迄今为止发现的所有靶向变性胶原蛋白的肽探针主要利用重复的（Gly-X-Y）序列，其中X和Y位置仅含有亚氨基酸Pro和Hyp，这稳定了肽探针的三螺旋构象，给它们的临床应用带来了严重障碍。通过在（GPO）GXO（GPO）序列的X位置掺入非亚氨基酸构建了一系列新型肽探针，同时X位点残基分别变为Tyr、Phe、Asp和Ala。在X位置含有芳香族残基Tyr和Phe的肽探针FAM-GYO和FAM-GFO与成熟的肽探针FAM-GPO表现出相似的高结合亲和力和组织染色效果，而具有相应带电残基Asp和疏水残基Ala的肽探针FAM-GDO和FAM-GAO则显示出弱得多的结合亲和力和组织染色能力。此外，FAM-GYO和FAM-GFO可以特异性检测不同类型小鼠结缔组织中的变性胶原蛋白，并有效染色各种人类病理组织。我们首次揭示，在重复的（Gly-X-Y）序列的X和Y位置掺入非亚氨基酸，特别是芳香族残基，可能提供一种方便的策略来创建新型的强大的靶向胶原蛋白的肽探针，这些探针在涉及胶原蛋白的疾病中具有广阔的诊断应用前景。
