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The Joshua Lederberg Papers

Title:
Letter from Joshua Lederberg to David M. Bonner pdf (57,074 Bytes) transcript of pdf
Letter from Joshua Lederberg to David M. Bonner
Number of Image Pages:
1 (57,074 Bytes)
Date:
1948-12-15 (December 15, 1948)
Creator:
Lederberg, Joshua
Recipient:
Bonner, David M.
Rights:
This item is in the public domain. It may be used without permission.
Subject:
Medical Subject Headings (MeSH):
Cell Culture Techniques
Mutation
Relation:
Lederberg Grouping: Correspondence B
Box Number: 6
Folder Number: 138
Unique Identifier:
BBAAFB
Accession Number:
1
Document Type:
Letters (correspondence)
Language:
English
Format:
application/pdf
image/tif
Physical Condition:
Good
Series: Correspondence, 1935-2002
SubSeries: 1947-1953
Folder: Bonner, David M.
Transcript:
December 15, 1948.
Dear Dave,
Your cultures all finally got here. Thanks very much.
I'm glad to hear that "ONPG" is working well for you. I've been studying the coli K-12 enzyme in more detail, with some very peculiar findings. The metal ions combine with the enzyme, and the major effect is not on the activity of the enzyme, as determined at infinite substrate concentration, but on the Ks; in a formal way, the alkali metal ions "compete" with the substrate, as well as with each other. This does not necessarily mean that they do absorb to the same sites on the enzyme molecule, but they alter the affinity of the enzyme for the substrate in the same way that a competitive inhibitor does (i.e. by increasing the slope of the 1/s term when 1/v is plotted against over 1/s). Lactose competes in accord with the Lineweaver-Burk formulation; in M/50 Na phosphate buffer, the Ks is 1.3 x 10-4; KI (lactose) is about ten times higher. Do you have some preparations with which the Nuerospora enzyme could be compared to the coli in these respects?
According to the grapevine, you've gotten several more lactose-negative mutants. Have you worked out a selective method?
Sincerely,
Metadata Last Modified Date:
2008-05-15
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