Biochemistry of copper

Chemistry

Most effective monovalent and divalent ions for binding organic molecules due to electron affinity

Means Cu+/Cu2+ effective as a redox couple

pi donor, so binds O2 and CO

Soft metal, so binds soft and borderline donor atoms such as sulfur and nitrogen

Most likely redox couple after the Great Oxygenation Event (before which it was Fe+/Fe2+)

Produced by electrowinning

Geobiochemical process in which copper sulfide is oxidised into copper sulfate by Thiobacillus ferroxidans which assimilates CO2

CuFeS2 + 4O2 -> CuSO4 + FeSO4

In vivo function

Tissue crosslinking

Free radical oxidases

In plants, by producing phenol.

Tissue browning in cooking

O2 transport

Haemocyanin

Cytochome oxidase

Electron transfer

Classification

Type 1

Type 2

Type 3

Haemocyanin

Copper blue proteins

Single Cu held by histidine, cysteine and methionine

Catalyses O2 + 4H -> 2H2O

Oxidases

Single copper ligated to four histidines, one of which is bound to a zinc atom also.

Cytochrome C has two haem centres and two copper centres.

Two potential binding modes - one has metal-metal bond and one has bridging sulfur.

Two copper ions coordinating three histidines each.

One O2 bound between two Cu ions

Oxygenation turns haemocyanin blue - hence why arthropods have blue blood!

Binding site for O2 in arthropods and molluscs.

Nutrition

Toxicity

Childhood cirrhosis

Caused by exposure from cooking utensils

Due to Fenton-like chemistry - Free radical production

Damages lipids and proteins

Deficiency

Arterial weakness and heart enlargement

Reduction in catecholamine neurotransmitters

Catecholamine neurotransmitter production

Health

Genetic disorders

Menke's syndrome

Amyotrophic lateral sclerosis (MS)

Degradation of the CNS

Wilson's disease

Copper buildup

Wound healing

Regulate expression of proteins involved in proliferation step

Well-known angiogenic factor (vascular regeneration)

Regulates vascular endothelial growth factor (VEGF)

Regulated Matrix metalloproteinases and TIMPs (tissue inhibitors of MMPs)

Application of small concentration of copper upregulates MMPs

Used as an antibiotic since ancient Egypt.