The prion challenge to the `central dogma' of molecular biology, 1965-1991 - part I: Prelude to prions

Since the 1930s, scientists studying the neurological disease scrapie had assumed that the infectious agent was a virus. By the mid 1960s, however, several unconventional properties had arisen that were difficult to reconcile with the standard viral model. Evidence for nucleic acid within the pathogen was lacking, and some researchers considered the possibility that the infectious agent consisted solely of protein. In 1982, Stanley Prusiner coined the term `prion' to emphasize the agent's proteinaceous nature. This infectious protein hypothesis was denounced by many scientists as `heretical'.This essay asks why the concept of an infectious protein was considered controversial. Some biologists justified their evaluation of this hypothesis on the grounds that an infectious protein contradicted the `central dogma of molecular biology'. Others referred to vague theoretical constraints such as molecular biology's `theoretical structure' or `framework'. Examination of the objections raised by researchers reveals exactly what generalizations were being challenged by a protein model of infection.This two-part survey of scrapie and prion research reaches several conclusions: (1) A theoretical framework is present in molecular biology, exerting its influence in hypothesis formation and evaluation; (2) This framework consists of several related, yet separable, generalizations or `elements', including Francis Crick's Central Dogma and Sequence Hypothesis, plus notions concerning infection, replication, protein synthesis, and protein folding; (3) The term `central dogma' has stretched beyond Crick's original 1958 definition to encompass at least two other `framework elements': replication and protein synthesis; and (4) From the study of scrapie and related diseases, biological information has been delineated into at least two classes: sequential and what I call `conformational'.In Part I of this essay, a brief review of the central dogma, as outlined by both Francis Crick and James Watson, will be given. The developments in scrapie research from 1965 to 1972 will then be traced. This section will summarize many of the puzzling, non-viral-like properties of the scrapie agent. Alternative hypotheses to the viral explanation will also be presented, including early versions of a protein-only hypothesis. Part II of this essay will follow the developments in scrapie and prion research from the mid 1970s through 1991. The growing prominence of a protein-only model of infection will be balanced by continued objections from many researchers to a pathogen devoid of nucleic acid. These objections will help illuminate those generalizations in molecular biology that were indeed challenged by a protein-only model of infection.
Keywords No keywords specified (fix it)
Categories (categorize this paper)
 Save to my reading list
Follow the author(s)
Edit this record
My bibliography
Export citation
Find it on Scholar
Mark as duplicate
Request removal from index
Revision history
Download options
Our Archive

Upload a copy of this paper     Check publisher's policy     Papers currently archived: 30,224
External links

Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
Through your library
References found in this work BETA

No references found.

Add more references

Citations of this work BETA

No citations found.

Add more citations

Similar books and articles
Collective Phenomena and the Neglect of Molecules: A Historical Outlook on Biology.U. Deichmann - 2007 - History and Philosophy of the Life Sciences 29 (1):83-86.
Reconstructing Life. Molecular Biology in Postwar Britain.S. Chadarevian - 2002 - Studies in History and Philosophy of Science Part C 33 (3):431-448.
The Prion Challenge to the `Central Dogma' of Molecular Biology, 1965–1991.Martha E. Keyes - 1999 - Studies in History and Philosophy of Science Part C 30 (2):181-218.
Crick's Notion of Genetic Information and the 'Central Dogma' of Molecular Biology.Predrag Šustar - 2007 - British Journal for the Philosophy of Science 58 (1):13-24.
Crick's Notion of Genetic Information and the ‘Central Dogma’ of Molecular Biology.Predrag Sustar - 2007 - British Journal for the Philosophy of Science 58 (1):13-24.
Added to PP index

Total downloads
39 ( #136,049 of 2,191,970 )

Recent downloads (6 months)
1 ( #289,023 of 2,191,970 )

How can I increase my downloads?

Monthly downloads
My notes
Sign in to use this feature