Identification and Nanomechanical Characterization of the HIV Tat‐Amyloid β Peptide Multifibrillar Structures

HIV transactivator of transcription (Tat) protein could interact with amyloid beta (Abeta) peptide which cause the growth of Abeta plaques in the brains and result in Alzheimer's disease in HIV-infected patients. Herein, we employ high-resolution atomic force microscopy and quantitative nanomechanical mapping to investigate the effects of Tat protein in Abeta peptide aggregation. Our results demonstrate that the Tat protein could bind to the Abeta fibril surfaces and result in the formation of Tat-Abeta multifibrillar structures. The resultant Tat-Abeta multifibrillar aggregates represent an increase in stiffness compared with Abeta fibrils due to the increase in beta-sheet formation. The identification and characterization of the Tat-Abeta intermediate aggregates is important to understanding the interactions between Tat protein and Abeta peptide, and the development of novel therapeutic strategy for Alzheimer's disease-like disorder in HIV infected individuals.