Temperature-dependent higher order structures of the (Pro-Pro-Gly)10-modified dendrimer

• Published in: Biopolymers 2011-04, Vol.95 (4), p.270-277
• Main Authors: Suehiro, Tomoyuki, Tada, Tomoko, Waku, Tomonori, Tanaka, Naoki, Hongo, Chizuru, Yamamoto, Shinya, Nakahira, Atsushi, Kojima, Chie
• Format: Article
• Language: English
• Subjects: biomimetic material; Circular Dichroism - methods; collagen; Collagen - chemical synthesis; Collagen - chemistry; Collagen - ultrastructure; dendrimer; Dendrimers - chemistry; Electron Microscope Tomography - methods; hydrogel; Magnetic Resonance Imaging - methods; Oligopeptides - chemistry; peptide; Peptides - chemical synthesis; Peptides - chemistry; Protein Conformation; Temperature; Thermodynamics; X-Ray Diffraction - methods
• ISSN: 0006-3525; 1097-0282; 1097-0282
• DOI: 10.1002/bip.21576

Collagen is the most abundant protein in mammals and is widely used as a biomaterial for tissue engineering and drug delivery. We previously reported that dendrimers and linear polymers, modified with collagen model peptides (Pro‐Pro‐Gly)5, form a collagen‐like triple‐helical structure; however, its triple helicity needs improvement. In this study, a collagen‐mimic dendrimer modified with the longer collagen model peptides, (Pro‐Pro‐Gly)10, was synthesized and named PPG10‐den. Circular dichroism analysis shows that the efficiency of the triple helix formation in PPG10‐den was much improved over the original. The X‐ray diffraction analysis suggests that the higher order structure was similar to the collagen triple helix. The thermal stability of the triple helix in PPG10‐den was higher than in the PPG10 peptide itself and our previous collagen‐mimic polymers using (Pro‐Pro‐Gly)5. Interestingly, PPG10‐den also assembled at low temperatures. Self‐assembled structures with spherical and rod‐like shapes were observed by transmission electron microscopy. Furthermore, a hydrogel of PPG10‐den was successfully prepared which exhibited the sol‐gel transition around 45°C. Therefore, the collagen‐mimic dendrimer is a potential temperature‐dependent biomaterial. © 2010 Wiley Periodicals, Inc. Biopolymers 95: 270–277, 2011.