March 13, 1956 - Linus Pauling Day-by-Day

Check from LP to Ingham, Coates, and Payne for $26.00. [Filed under LP Biographical: Business and Financial: Bank Statements and Canceled Checks, February 1956-December 1957: Box #4.024, Folder #24.1] [Also filed under LP Biographical: Business and Financial: Check Registers, 1951-1960: Box #4.075, Folder #75.3]

Letter from J. English, Yale University, to LP RE: Asks if LP could give a talk in the Department of Chemistry while in New Haven in April. [Letter from LP to English March 16, 1956] [Filed under LP Correspondence: (E: Correspondence, 1956), #112.22]

Letter from LP and AHP to Board of Regents, American College of Physicians, RE: Accept invitation for the Reception and Dinner at 7 PM on April 15 at the Biltmore Hotel in Los Angeles. [Filed under LP Speeches: 1956s.16]

Letter from LP to Arthur L. Pollard, Biological Laboratory Knoxville, TN, RE: Expresses his interest in the micro-helical structures displayed in the photomicrographs Pollard sent him. [Letter from Pollard to LP March 7, 1956] [Filed under LP Correspondence: (P: Correspondence, 1956), #313.4]

Letter from LP to Dr. C.E. Cummings, Texas Laboratory, RE: LP gives Stanley L. Grotch a good recommendation. [Letter from Cummings to LP March 13, 1956] [Filed under LP Science: John Simon Guggenheim Memorial Foundation, 1953-1975: Box #14.015, Folder #15.4]

Letter from LP to Dr. Frank D. White, Biochemistry Dept., University of Manitoba, RE: Accepts invitation to dine with White and his wife on Wednesday. The other arrangements seem satisfactory. [Letter from ,White to LP March 8, 1956] [Filed under LP Speeches: 1956s.9]

Letter from LP to Dr. R.B. Berkoff, Secretary, Manitoba Section, Chemical Institute of Canada, RE: Will keep noon on March 31 free in case Berkoff arranges a luncheon meeting of the Section. [Letter from Berkoff to LP March 6, 1956] [Filed under LP Speeches: 1956s.9]

Letter from LP to G.B.B.M. Sutherland, University of Michigan, RE: Congratulates Sutherland on his appointment as Director of the National Physical Laboratory. [Letter from Sutherland to LP March 27, 1956] [Filed under LP Correspondence: (Sutherland, G.B.B.M, 1939, 1956), #341.2]

Letter from LP to Professor Ralph A. Beebe, Chemistry Dept., Amherst College, RE: LP and AHP plan to drive from New Haven to Amherst on April 25 and arrive in the middle of the afternoon. Would like to attend Thurgood Marshall's lecture that evening. LP will lecture on April 26 at 8 PM and then deliver a chemistry seminar talk on April 27 at 4:30 PM, perhaps on the structure of proteins. [Letters from Beebe to LP March 7, 1956, March 21, 1956] [Filed under LP Speeches: 1956s.19]

Letter from Maria Migliorini, student at St. Clement High, to LP RE: Requests information regarding LP's studies of protein molecules in regard to mutation, disease and amino acids for use in a science fair project. [Filed under LP Correspondence: (M: Correspondence, 1956), #257.1]

Letter from Vasudev A. Vyas, Dharmendrasinhji College, to LP RE: Hopes to do post-doctoral work at Caltech under LP's supervision. Outlines his qualifications. [Letter from LP to Vasudev A. Vyas March 22, 1956] [Filed under LP Correspondence: (V: Correspondence, 1956), #427.16]

Memo from LP to Miss Walter RE: Attached is an application to the Public Health Service for renewal of Research Grant 4276, requests that the application be signed and sent off to Public Health Services. Supporting materials attached. [Filed under LP Science: United States Public Health Service: Assorted Grants, 1954-1964: Box #14.042, Folder #42.1]

Memo from LP to Robert B. Corey. [Filed under LP Manuscripts of Articles: 1956a.4]

TO R. B. Corey FROM Linus Pauling DATE 13 March 1956

SUBJECT Proposed calculation, relating to crystalline globular proteins

I suggest that you have Dr. Marsh and assistants carry out a calculation as a test of methods of determining the structure of crystalline globular proteins.

The simple calculation involves the formulation of a one-dimensional structure, the calculation of the real and the imaginary parts of the amplitude of the scattered wave, A and B, and the use of these values, extending over various ranges of interatomic distances, to evaluate various Fourier series, in order to see what ranges of interatomic distances must be used to get resolution of atoms and identification of atoms.

I suggest that the work be done, as a first step, roughly in the following way. Let us take a one-dimensional structure, with a₀ = 30 A. The unit is to have one Fe at 0.000, one Cl at 0.210, and 12 C at 0.080, 0.125, 0.290, 0.370, 0.420, 0.470, 0.540, 0.630, 0.700, 0.750, 0.840, and 0.900. These coordinates make interatomic distances along the line cover the range from 1.35 A to 3.00 A. I suggest that A and B be calculated for orders h from 1 to 30, representing interplanar distances from 30 A to 1 A. The f value of carbon might be used as the basis of the calculation; I think that it would be good enough to take that for chlorine as 3 times that for carbon, and for iron as 5 times that for carbon.

These values of A and B could then be used to evaluate the Fourier series representing the electron density, by a number of different calculations, corresponding to use of orders of reflection as follows: 1 to 30; 6 to 30; 8 to 30; 10 to 30; 15 to 30; 10 to 20; 10 to 15; others indicated by the results.

The Fourier series obtained in this way could be discussed with respect to errors in the coordinates of each atom, and also in the height of the peak representing each atom. What limitation of the range causes an atom to be missed? What limitation of the range leads to the introduction of phantom atoms - peaks in positions where no atom was present?

After these questions have been answered, a suitable range may be selected, perhaps 10 to 30, reflections from 3 A to 1 A spacing, and the calculation repeated after random 10% errors have been introduced into the values of A and B.

Probably the next step that will have to be made is to carry out a similar calculation for a two-dimensional structure, involving about 100 atoms. It might be possible to generalize from the results of the one-dimensional problem and the two-dimensional problem to conclusions valid for the three-dimensional problem; but it probably will be worth while to carry out some sort of detailed theoretical treatment of this sort also for the three-dimensional problem.

(signed) L. P.

Linus Pauling:W

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