title: Influence of neutral salts on the hydrothermal stability of acid-soluble collagen.
abstract: The thermal stability of acid-soluble collagens was studied by circular dichroism (CD) spectroscopy. Adult bovine dermal collagen (BDC), rat-tail tendon collagen (RTC), and calf skin collagen (CSC) were compared. Despite some variability in amino acid composition and apparent molecular weight, the CD spectra for helical and unordered collagen structures were essentially the same for all the sources. The melting of these collagens occurs as a two-stage process characterized by a pretransition (Tp) followed by complete denaturation (Td). The characteristic temperatures vary with the source of the collagen; for mature collagens (BDC, RTC) Tp = 30 degrees C and Td = 36 degrees C, and for CSC Tp = 34 degrees C and Td = 40 degrees C. Neutral salts, NaCl or KCl, at low concentrations (0.02-0.2 M) appear to bind to the collagens and shift the thermal transitions of these collagens to lower temperatures.
authors.affiliation: Eastern Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania 19038, USA. ebrown@arserrc.gov
authors.forename: E M
authors.initials: EM
authors.lastname: Brown
authors.forename: H M
authors.initials: HM
authors.lastname: Farrell
authors.forename: R J
authors.initials: RJ
authors.lastname: Wildermuth
mesh_terms: D000143:Acids / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D003094:Collagen / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D015394:Molecular Structure; D008970:Molecular Weight; D010084:Oxidation-Reduction; D011489:Protein Denaturation; D051381:Rats; D012492:Salts / Q000737:chemistry* / Q000378:metabolism; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000143:Acids; D000596:Amino Acids; D012492:Salts; D003094:Collagen