Thermal Sensitivity of Calcium and Magnesium Binding for Parvalbumins from Teleost Fish

• Other Authors: Erickson, Jeffrey Robert (authoraut), Moerland, Timothy S. (professor directing dissertation), Logan, Timothy M. (outside committee member), Chase, P. Bryant (committee member), Ellington, W. Ross (committee member), Gaffney, Betty J. (committee member), Department of Biological Science (degree granting department), Florida State University (degree granting institution)
• Format: Text
• Language: English
• Published: Florida State University
• Subjects: Medical sciences; Antarctic; Arctic; Bryant; Antarc*; Boreogadus saida
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-0553; http://fsu.digital.flvc.org/islandora/object/fsu%3A168702/datastream/TN/view/Thermal%20Sensitivity%20of%20Calcium%20and%20Magnesium%20Binding%20for%20Parvalbumins%20from%20Teleost%20%20%20%20%20%20%20%20%20%20Fish.jpg

Parvalbumin is an abundant divalent cation binding protein of fast vertebrate skeletal muscle. Its proposed function is to sequester calcium after contraction, thus facilitating relaxation. Calcium and magnesium equilibrium dissociation constants and instantaneous rate constants of parvalbumins from two Antarctic teleosts (Gobionotothen gibberifrons and Chaenocephalus aceratus), two temperate zone teleosts (Cyprinus carpio and Micropterus salmoides), and one Arctic teleost (Boreogadus saida) were determined to assess potential differences in protein function. PV was isolated by homogenization followed by gel filtration and ion exchange chromatography. Sample purity was checked by 2-D PAGE. Dissociation constants were determined by a competitive binding assay between parvalbumin and either fluo-3 or Magnesium Green. Thermodynamic parameters were determined by calorimetry. Instantaneous rate constants were determined by stopped-flow spectrometry. Deduced amino acid sequences were also determined for several teleost parvalbumins. Functional data showed that parvalbumins from different teleost fish can exhibit markedly different patterns of thermal sensitivity. However, a general pattern of conservation for several binding parameters at native temperature was observed. Sequence data indicated that the major structural features, including the coordinating residues of the binding loops, were conserved in parvalbumins. Substitutions leading to variability of thermal function are likely to have occurred outside the binding loops of the protein. A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Degree Awarded: Fall Semester, 2005. Date of Defense: September 19, 2005. Parvalbumin, Muscle, Temperature Includes bibliographical references. Timothy S. Moerland, Professor Directing Dissertation; Timothy M. Logan, Outside Committee Member; P. Bryant Chase, Committee Member; W. Ross Ellington, Committee Member; Betty J. Gaffney, Committee Member.