Primary structure and spectroscopic studies of Neurospora copper metallothionein

Journal Article · Sat Mar 01 00:00:00 EST 1986 · Environ. Health Perspect.; (United States)

DOI:https://doi.org/10.1289/ehp.866521· OSTI ID:5386408

Beltramini, M; Lerch, K

When Neurospora crassa is grown in the presence of Cu(II) ions, it accumulates the metal with the concomitant synthesis of a low molecular weight copper-binding protein. The molecule binds 6 g-atom of copper per mole protein (M/sub r/ = 2200) and shows a striking sequence homology to the zinc- and cadmium-binding vertebrate metallothioneins. Absorption, circular dichroism, and electron paramagnetic resonance spectroscopy of Neurospora metallothionein indicate the copper to be bound to cysteinyl residues as a Cu(I)-thiolate complex of the polymeric ..mu..-thiolate structure (Cu(I)/sub 6/RS/sub 7/)/sup -/. The spectroscopic properties of the fully substituted forms are indicative of a distorted tetrahedral coordination. However, metal titration of the apoprotein shows the third metal ion to be differently coordinated than the other two metal ions. This difference can be explained by the presence of only seven cysteine residues in Neurospora metallothionein as opposed to nine cysteine residues in the three-metal cluster of the mammalian metallothioneins.

• Research Organization: Univ. of Padova, Italy
• OSTI ID: 5386408
• Journal Information: Environ. Health Perspect.; (United States), Vol. 65
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
METALLOTHIONEIN
BIOSYNTHESIS
SPECTROSCOPY
STOICHIOMETRY
COPPER
NEUROSPORA
ELEMENTS
FUNGI
METALLOPROTEINS
METALS
ORGANIC COMPOUNDS
PLANTS
PROTEINS
SYNTHESIS
TRANSITION ELEMENTS
550200* - Biochemistry
560302 - Chemicals Metabolism & Toxicology- Microorganisms- (-1987)