Resource Type

Metal-Tyrosyl Coordination in Transferrin. 2. Difference Ultraviolet Spectroscopy of Di-, Tri-, and Tetravalent Metal Ions With Ethylene-Bis(0-Dydroxyphenylgly-Cine). (open access)

Metal-Tyrosyl Coordination in Transferrin. 2. Difference Ultraviolet Spectroscopy of Di-, Tri-, and Tetravalent Metal Ions With Ethylene-Bis(0-Dydroxyphenylgly-Cine).

In order to probe the metal ion coordination site in the human iron transport protein, transferrin, the complexation of a series of metal ions by the chelate analogue ethylene-bis(o-hydroxyphenylglycine) (EHPG) has been studied by difference uv spectroscopy, in which {Delta}{epsilon} values per coordinated phenol have been determined for the metal complex versus the protonated form of the ligand. With the exception of the.Cu {sup 2+} complex, maxima are observed at 242 nm and 290 nm with a minimum at 269 nm. The {Delta}{epsilon} values at 242 fall into two groups. Complexes of divalent metal ions (Zn{sup 2+}, Cu{sup 2+}, Cd{sup 2+}) have 6£ values ranging from 5000 to 6600 M{sup -1} cm{sup -1} whereas larger {Delta}{epsilon} values are observed for complexes of tri- and tetra- valent metal ions (Th{sup 4+}, Ga{sup 3+}, Fe{sup 3+}, • Ho{sup 3+}, Eu{sup 3+}, Er{sup 3+}, Tb{sup 2+}, VO{sup 2+}), 7400 - 8700 M{sup -1} cm{sup -1}. It is known that the transferrin binding sites contain tyrosyl residues, but there has been considerable debate concerning the precise number of tyrosine groups which bind to specific metal ions. Since it has been the common practice to assume the {Delta}{epsilon} values for coordination by all metal ions …
Date: August 1, 1980
Creator: Pecoraro, Vincent L.; Harris, Wesley R.; Carrano, Carl J. & Raymond, Kenneth N.
System: The UNT Digital Library
Exact integrability in quantum field theory (open access)

Exact integrability in quantum field theory

The treatment of exactly integrable systems in various branches of two-dimensional classical and quantum physics has recently been placed in a unified framework by the development of the quantum inverse method. This method consolidates a broad range of developments in classical nonlinear wave (soliton) physics, statistical mechanics, and quantum field theory. The essential technique for analyzing exactly integrable quantum systems was invested by Bethe in 1931. The quantum-mechanical extension of the inverse scattering method and its relationship to the methods associated with Bethe's ansatz are examined here. (RWR)
Date: August 1, 1980
Creator: Thacker, H.B.
System: The UNT Digital Library
Proceedings of the sixth international conference on fluidized bed combustion. Volume 3. Technical sessions (open access)

Proceedings of the sixth international conference on fluidized bed combustion. Volume 3. Technical sessions

The Sixth International Conference on Fluidized Bed Combustion was held April 9-11, 1980, at the Atlanta Hilton, Atlanta, Georgia. It was sponsored by the US Department of Energy, the Electric Power Research Institute, the US Environmental Protection Agency, and the Tennessee Valley Authority. Forty-five papers from Vol. III of the proceedings have been entered individually into EDB and ERA. Two papers had been entered previously from other sources. (LTN)
Date: August 1, 1980
Creator: unknown
System: The UNT Digital Library