Heparin binding by the HIV‐1 tat protein transduction domain

• Published in: Protein science Vol. 10; no. 10; pp. 2138 - 2139
• Main Authors: Hakansson, Susanna, Jacobs, Amy, Caffrey, Michael
• Format: Journal Article
• Language: English
• Published: Bristol Cold Spring Harbor Laboratory Press 01-10-2001
• Subjects: For the Record; Gene Products, tat - metabolism; Heparan sulfate; heparin; Heparin - metabolism; Heparitin Sulfate - metabolism; HIV; HIV-1 - chemistry; IPTG, isopropyl‐b‐D‐thiogalactopyranoside; Nerve Tissue Proteins - metabolism; PG, IgG binding domain of streptococcal protein G; PG‐Ctat, HIV‐1 tat PTD domain fused to C‐terminus of PG; Protein Structure, Tertiary - physiology; protein transduction; Protein Transport; PTD, protein transduction domain; PTD‐tat, HIV‐1 tat PTD domain; Streptococcus - chemistry; tat; tat Gene Products, Human Immunodeficiency Virus
• ISSN: 0961-8368; 1469-896X
• DOI: 10.1110/ps.23401

The protein transduction domain from the HIV‐1 tat protein (termed PTD‐tat) has been fused to the C‐terminus of a model cargo protein, the IgG binding domain of streptococcal protein G. We demonstrate that PG‐Ctat (PTD‐tat fused to the C‐terminus of protein G) binds to a heparin affinity column. PG‐Ctat binds with relatively high affinity, as shown by its elution at 1.6 M NaCl. The heparin binding properties of PTD‐tat are consistent with the idea that heparan sulfate, an analog of heparin found at the cell surface, plays a role in the translocation of PTD‐tat fusions. We suggest that the heparin‐binding properties of PTD‐tat can be exploited for purification of PTD‐tat fusions in the absence of affinity tags.