title: Temperature induced denaturation of collagen in acidic solution.
abstract: The denaturation of collagen solution in acetic acid has been investigated by using ultra-sensitive differential scanning calorimetry (US-DSC), circular dichroism (CD), and laser light scattering (LLS). US-DSC measurements reveal that the collagen exhibits a bimodal transition, i.e., there exists a shoulder transition before the major transition. Such a shoulder transition can recover from a cooling when the collagen is heated to a temperature below 35 degrees C. However, when the heating temperature is above 37 degrees C, both the shoulder and major transitions are irreversible. CD measurements demonstrate the content of triple helix slowly decreases with temperature at a temperature below 35 degrees C, but it drastically decreases at a higher temperature. Our experiments suggest that the shoulder transition and major transition arise from the defibrillation and denaturation of collagen, respectively. LLS measurements show the average hydrodynamic radius R(h), radius of gyration R(g)of the collagen gradually decrease before a sharp decrease at a higher temperature. Meanwhile, the ratio R(g)/R(h) gradually increases at a temperature below approximately 34 degrees C and drastically increases in the range 34-40 degrees C, further indicating the defibrillation of collagen before the denaturation.
authors: Department of Pharmaceutics and Bioengineering, Key Lab of Leather Chemistry, and Engineering of Ministry of Education, Sichuan University, Chengdu, China.
authors: Changdao
authors: C
authors: Mu
authors: Defu
authors: D
authors: Li
authors: Wei
authors: W
authors: Lin
authors: Yanwei
authors: Y
authors: Ding
authors: Guangzhao
authors: G
authors: Zhang
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D003094:Collagen / Q000378:metabolism*; D011489:Protein Denaturation; D012996:Solutions; D013696:Temperature; D044366:Transition Temperature
chemical_list: D012996:Solutions; D003094:Collagen; D019342:Acetic Acid