Cho, Se Youn Yun, Young Soo Lee, Sungho Jang, Dawon Park, Kyu-Young Kim, Jae Kyung Kim, Byung Hoon Kang, Kisuk Kaplan, David L. Jin, Hyoung-Joon 2024-01-20T07:03:39Z 2024-01-20T07:03:39Z 2021-09-05 2015-05 2041-1723 https://pubs.kist.re.kr/handle/201004/125486 Silk proteins are of great interest to the scientific community owing to their unique mechanical properties and interesting biological functionality. In addition, the silk proteins are not burned out following heating, rather they are transformed into a carbonaceous solid, pyroprotein; several studies have identified potential carbon precursors for state-of-the-art technologies. However, no mechanism for the carbonization of proteins has yet been reported. Here we examine the structural and chemical changes of silk proteins systematically at temperatures above the onset of thermal degradation. We find that the beta-sheet structure is transformed into an sp2-hybridized carbon hexagonal structure by simple heating to 350 degrees C. The pseudographitic crystalline layers grew to form highly ordered graphitic structures following further heating to 2,800 degrees C. Our results provide a mechanism for the thermal transition of the protein and demonstrate a potential strategy for designing pyroproteins using a clean system with a catalyst-free aqueous wet process for in vivo applications. English NATURE PUBLISHING GROUP BOMBYX-MORI SILK SPIDER SILK CARBON SPECTROSCOPY TRANSITION BEHAVIOR FIBERS Carbonization of a stable beta-sheet-rich silk protein into a pseudographitic pyroprotein Article 10.1038/ncomms8145 1 NATURE COMMUNICATIONS, v.6 NATURE COMMUNICATIONS 6 scie scopus 000355533700004 2-s2.0-84930221997 Multidisciplinary Sciences Science & Technology - Other Topics Article BOMBYX-MORI SILK SPIDER SILK CARBON SPECTROSCOPY TRANSITION BEHAVIOR FIBERS silk fiber carbon fiber carbonization pyroprotein