(1906-1979) German-born British biochemist. After the discovery of penicillin by Alexander Fleming, Chain worked to isolate and purify it. For this work, he shared the 1945 Nobel Prize for Medicine with Fleming and Howard Florey. Chain also discovered penicillinase, an enzyme that destroys penicillin.
Born and educated in Berlin, Chain fled to Britain from the Nazis 1933. He worked at Cambridge University 1933–35, and then with Florey at Oxford. In 1949 Chain was invited to the Istituto Superiore di Sanità in Rome; he stayed there as professor until 1961, when he returned to the UK as professor of biochemistry at Imperial College, London.
At Oxford, Chain initially investigated the observation first made by Fleming 1924 that tears, nasal secretion, and egg white destroy bacteria. Chain showed that these substances contain an enzyme, lysozyme, which digests the outer cell wall of bacteria. In 1937 Chain found another observation of Fleming’s, that the mold Penicillium notatum inhibits bacterial growth. In collaboration with Florey, Chain isolated and identified the antibacterial factor in the mold.
Chain then elucidated the chemical structure of crystalline penicillin, finding that there are four types, each differing in its relative elemental constituents.
Chain also studied snake venoms and found that the neurotoxic effect of these venoms is caused by their destroying an essential intracellular respiratory coenzyme.

ETYM French chaîne, from Latin catena. Related to Catenate.
Unit of length equal to 20 metres.
1. A series of (usually metal) rings or links fitted into one another to make a flexible ligament.
2. A number of similar establishments (stores or restaurants or banks or hotels or theaters) under one ownership.
3. A series of things depending on each other as if linked together; SYN. concatenation.
4. Anything that acts as a restraint.
5. A series of linked atoms (generally in an organic molecule); SYN. chemical chain.
6. A unit of length.

To fasten or secure with chains

A fern of the genus Woodwadia having the sori in chainlike rows.

A gang of convicts chained together.
A gang of people (as convicts) chained together especially as an outside working party

A letter that is sent successively to several people. chain-letter