Kaptain

H. F. Bienfait, H. J. Lubberding, P. Heutink, L. Linder, J. Visser, R. Kaptain and K. Dijkstra, Rhizosphere aeidilication by iron deficient bean plants the role of trace amounts of divalent metal ions. Plant Physiol. 90 359 (1989). 

Kaptain obtained the time evolution of the wave function ( P(r)) of a radical pair during the S-To conversion [3], solving the Schrodinger equation. 

T cases. During their first encounter, a fraction of singlet pairs ( Q(0) = 1/4) combines with a rate of A and the remainder has a chance of meeting again. In Ref [1], Kaptain showed that the total fraction of pairs (Pn), with nuclear state N that recombines, would be given by the following relation with a similar treatment used for P, -. 

Such anomalous NMR spectra as observed in the above reactions have been called Chemically Induced Dynamic Nuclear Polarization (CIDNP) . CINDP should be due to nonequilibrium nuclear spin state population in reaction products. At first, the mechanism of CIDNP was tried to be explained by the electron-nuclear cross relaxation in free radicals in a similar way to the Overhauser effect [4b, 5b]. In 1969, however, the group of Closs and Trifunac [6] and that of Kaptain and Oosterhoff [7] showed independently that all published CIDNP spectra were successfully explained by the radical pair mechanism. CIDEP could also be explained by the radical pair mechanism as CIDNP. In this and next chapters, we will see how CIDNP and CIDEP can be explained by the radical pair mechanism, respectively. 

In this section, several typical CINPD spectra will be shown. These spectra can be explained by Kaptain s rules. Typical net absorptive and emissive CINDP signals were observed during the thermal decomposition of acetyl peroxide (AP) in hexachloroacetone at 110 °C as shown in Fig. 4-8. Here, enhanced absorptive signals were observed for CH3CI and CH4 and emissive ones for CH3COOCH3 and CH3-CH3. 

In Section 3.3, we considered the S-To conversion of radical pairs with the method of Kaptain. In this section, we will reconsider the S-To conversion with the method of the density matrix [2]. In Eq. (11-25), we take the two basic functions as follows ... 

T. A. Rouault, C.D. Stout, S. Kaptain, J.B. Harford, and R.D. Klausner. 1991. Structural relationship between an iron-regulated RNA-binding protein (IRE-BP) and aconitase Functional implications Cell 64 881-883. (PubMed)... 

Seidman AD, Former MN, Esteva FJ, Tan L, Kaptain S, Bach A, Panageas KS, Arroyo C, Valero V, Currie V, Gilewski T, Theodoulou M, Moynahan ME, Moasser M, Sklarin N, Dickler M, D Andrea G, Cristofanilli M, Rivera E, Hortobagyi GN, Norton L, Hudis CA. Weekly trastuzumab and paclitaxel therapy for metastatic breast cancer with analysis of efficacy by HER2 immunophenotype and gene amplification. J Clin Oncol 2001 19(10) 2587-95. 

Here, Oij is positive when nuclei i and j are located on the same radical, but oj is negative when nuclei i and j are located on the different radicals. The fourth term [ ] of Eq. (4-15c) is not so important because it vanishes when Mt is 1/2. This is the case for proton-, C-, and F-NMR. Eqs. (4-17) and (4-22) are called Kaptain s rules, which are very useful for the interpretation of CIDNP spectra. 

Kaptain S, Downey WE, Tang C, Philpott C, Haile D, Orloff DG, Harford JB, Rouault TA, Klausner RD. A regulated RNA binding protein also possesses aconi-tase activity. Proc Natl Acad Sci USA 1991 88 10109-10113. 

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