Methods We tested the binding of a set of 31 synthetic TSHR extracellular domain peptides to eight HLA molecules in vitro by ELISA,determined the TSHR peptides which could bind with high affinity to the susceptibility gene of GD(HLA-DR3 and HLA-DQA1*0501) by calculating their IC50 values,and their binding ability to the protective gene of GD(HLA-DR7 and HLA-DQA1*0201) was also tested.

Objective To identify the immunogenic epitope of thyroid-stimulating hormone receptor(TSHR) that is involved in the pathogenesis of Graves' disease(GD) as auto-antigens by detecting the binding ability of human TSHR peptides and human leukocyte antigen(HLA) molecules.

目的通过检测人促甲状腺激素受体(thyroid-stimu lating hormone receptor,TSHR)多肽片段与人白细胞抗原(hum an leukocyte antigen,HLA)分子的结合力,寻找人TSHR作为自身抗原导致G raves病的多肽位点。

The radioligand-receptor binding assay showed that the binding of [3H] FNZP to translated benzo-diazepine receptors was saturable and specific(KD= 1.17nmol/L,Bmax=1.5fmol/cell).

By the induction of IFN-γ,the binding rate and Ncpm of ~(131)I-Herceptin in the three cell lines increased by different degrees. When IFN-γ was 500U/ml or 1000U/ml,the binding rate increased significantly(P<0.05).

However, the binding level increased significantly as rats and mice developed from d 0 to d 28 , and reached the maximal binding on d 28 and then decreased slowly.

In addition, the slight difference for the k cat values between the R 130L and R 130L/S 131A mutants suggested that Arg 130 mutation disrupted the hydrogen bond between Ser 131 and Cys 124. Furthermore, the arsenate binding affinity for R 125L, R 130L and R 158L mutants was decreased, suggesting that positive charges in the side chains of these three arginine residues may be helpful for the binding of the enzyme to the substrate.

The binding of 2′-dAMP and 5′-AMP may resultin different conformational changes on fructose 1,6-bisphosphatase and the interactionof 2′-OH of 5′-AMP with a certain group at the allosteric site of the enzyme wouldconduct the transmission of the message from the allosteric site to the catalytic site.

Firstly, by docking two classes of VEGFR inhibitors into the activity cavity ofKDR using AutoDock3.05, we identified the binding conformation of the inhibitorsand the functionally important residues of the active cavity of KDR.

CONCLUSION The differences in the amount of esteratic site available for soman detoxification and the binding rate between soman and detoxifying enzymes might be responsible for the species variation of detoxification capability in blood.

Ultraviolet (UV) melting curves of the DNA at 260 nm as well as the calorimetric measurements were used to estimate the binding constants (K), melting enthalpy (ΔH°m) and binding enthalpy (ΔH°b).

In order to search for better acetylcholinesterase (AchE) inhibitors, the binding properties of AchE with huperizine E, which is a derivative of huperzine A, were investigated with 1H nuclear magnetic resonance (1H NMR) method.

According to the electrochemical equation deduced in this paper, the binding constant of 1.36 × 105 (mol/L)-1 and the binding size of 1.94 (base pairs) of CFX with ctDNA were obtained by nonlinear fit analysis of the electrochemical data.

This work attempts to calculate the binding-site number using fluorescence spectroscopic method with bovine serum albumin (BSA) and Indo-1 as protein and ligand models, respectively.

The method for calculating the binding-site number in BSA for Indo-1 was developed based on the relationships between changes in Indo-1 fluorescence intensity and the analytical concentration of BSA.

A new approximation method is proposed in this article for the discussion of molecular structures,and this new method includes the two well-known theories,molecular orbital theory and electron-pair bond theory as two special cases.Let a molecule have n bonds and let the ith bond be described by the anti-symmetrical two-electron bond function ψ_i(v_(2i-1),v_(2i)).(If there exist one- electron,three-electron or many-electron bonds,they can be similarly described by the corresponding one-electron,three-electron...

A new approximation method is proposed in this article for the discussion of molecular structures,and this new method includes the two well-known theories,molecular orbital theory and electron-pair bond theory as two special cases.Let a molecule have n bonds and let the ith bond be described by the anti-symmetrical two-electron bond function ψ_i(v_(2i-1),v_(2i)).(If there exist one- electron,three-electron or many-electron bonds,they can be similarly described by the corresponding one-electron,three-electron or many-electron bond func- tions.) Then the stationary state of the molecule is represented by the follow- ing wave function Ψ, where the summation is over all permutations of 1,2,……,2n except those within the interior of the functions,since each ψ_i is already anti-symmetrical.Obviously (2~n/((2n)/!))~(1/2) is the normalization factor. By quantum mechanics the energy of the molecule equals (1) here H_i,T_(ij) and S_(11)' are respectively the following three kinds of operators, (2) (3) (4) The third term of equation (1) is the exchange integral of electrons 1 and 1', while (1,2') is that of electrons 1 and 2'.According to the definition of bond functions,ψ_i may be written as (5) Substituting equation (5) into equation (1) and carrying out the integration over spin coordinates,we obtain (6) It can be easily seen from equation (6) that the combining energy of a mole- cule consists of two parts,one being the binding energy of the bonds represent- ed by the first term of equation (6),and the other being the interaction energy of the bonds denoted by the second term of that equation. If we choose certain functions φ_i~('s) involving several parameters and substi- tute them into equation (6),we may determine the values of those parameters by means of the variation principle. For the discussion of bond interaction energies,we develop a new method for the evaluation of certain types of three-center and four-center integrals.The interaction energy of a unit positive charge and an electron cloud of cylindrical- symmetry distribution may be written as (7) where (8) and R_0~2=a~2+b~2+c~2 The interaction energy of two electron clouds both of cylindrical-symmetry distributions with respect to their own respective axes is evaluated to be (9) (10) where is to sum over j from zero to the lesser value of n-2i and m, is to sum over i from zero to the integral one of n/2 and (n-1)/2,and is to sum over all cases satisfying the relation =m-j,while b_(n,n-2i) represents the coefficient of x~(n-2i) in the n th Legendre polynomial.

Although James and Coolidge (1933) solved the molecular hydrogen problem in almost complete agreement with experiment by using a 13-term 2-electron eigenfunction, his method can hardly be applied to more complex molecules. For this and other reasons (Coulson, 1938), it is still desirable to obtain a good one-electron eigenfunction, i.e., molecular orbital, for the hydrogen molecule. The best molecular orbital treatment available in the literature was given by Coulson (1938), who used a trial eigenfunction in...

Although James and Coolidge (1933) solved the molecular hydrogen problem in almost complete agreement with experiment by using a 13-term 2-electron eigenfunction, his method can hardly be applied to more complex molecules. For this and other reasons (Coulson, 1938), it is still desirable to obtain a good one-electron eigenfunction, i.e., molecular orbital, for the hydrogen molecule. The best molecular orbital treatment available in the literature was given by Coulson (1938), who used a trial eigenfunction in elliptical coordinates involving 5 parameters and obtained 3.603 eV for the binding energy of H_2, which is to be compared with the ex- perimental value of 4.72 eV. In the present investigation we have proposed a new type of trial eigenfunction for the molecular orbital: (1) with p = centers a, b, g, c, d,…… i = electron 1 or 2 (2) where the p's are centers along the bond axis a-b (Fig. 1). In this simple problem both the Fock and Hartree methods yield the same result. The molecular orbital ψ must satisfy the following integral equation: (3) where ε is the energy of the molecular orbital, F is the Fock operator which is equal to H+G(1), while H is the one-electron Hamiltonian operator: H = -1/2▽~2-1/r_a-1/r_b (4) and G(1) is the interaction potential (5) Substituting (1) into (3), we obtain the linear combination coefficients c_p, which must satisfy the following secular equation: (6) where is the solution of the secular determinant and The F_(pq)'s are not at first known, but depend upon the c_p's. A method of successive approximation must therefore be adopted. A set of c_p values may be assumed, the F_(pq)'s calculated, the secular determinant (7) solved, and a new set of c_p values found. This process is repeated until a "self-consistent" set of c_p values is obtained. The above procedure was first proposed by Roothaan (1951), not for H_2 but for more complex molecules. It was called by him the "LCAO SCF (linear combination of atomic orbitals self-consistent field) method". The new feature of the present investigation is that we not only use LCAO but also LCNAO (linear combination of non-atomic orbitals, such as x_g, x_c, x_d, …). The order of secular determinant (7) may be reduced to half if we replace the eigen- functions x_a, x_b .... by their symmetrical and anti-symmetrical linear combinations x_a + x_b and x_a-x_b. Numerical calculations have been carried out both for the three- and the two-centered molecular orbitals. The three-centered molecular orbital is (10) (11) where S_(ab) and S(ag) are the overlapping integrals between x_a and x_b, and between x_a and x_g respectively. The parameters a and g have 'been obtained to give minimum energy by the method described above. They are a=l.190, g=0.22, and the binding energy is 3.598 eV, which is almost as good as that obtained by Coulson (3.603 eV) using a trial function of 5 parameters. The two-centered molecular orbital is (12) (13) which gives a maximum binding energy of 3.630 eV for a=1.190 and R~(ac)=R(bd)=0.105 (Fig. 1). This result is 'better than Coulson's. If we allow different values for the ex-ponent α in x_a and x_g in equation (11), or if we use a four-centered molecular orbital, such as ψ=a(x_a + x_b) + b(x_c + x_d) with four parameters, namely α_a=α_b, α_c=α_d, R_(ac)=R_(bd) and the ratio b/a, it is possible to obtain a still better result. Extension of the present method to the treatment of more complex molecules is now under investigation.

An internal friction peak induced by carbon diffusion has been observed in f. c. c. iron-nickel alloys. At a vibrational frequency of 1.4 cycles per sec., the peak occurs at about 500°K. This peak arises from the preferential rotation of the axes of carbon pairs existed in the specimen under the influence of an alternating load. These carbon pairs were formed by the interaction between the substitutional carbon atoms and their neighboring interstitial carbon atoms. Based upon this mechanism and considering the...

An internal friction peak induced by carbon diffusion has been observed in f. c. c. iron-nickel alloys. At a vibrational frequency of 1.4 cycles per sec., the peak occurs at about 500°K. This peak arises from the preferential rotation of the axes of carbon pairs existed in the specimen under the influence of an alternating load. These carbon pairs were formed by the interaction between the substitutional carbon atoms and their neighboring interstitial carbon atoms. Based upon this mechanism and considering the possible redistribution of the carbon atoms amongst the frozen-in vacancies in the specimen during the course of internal friction measurement, an equation bearing the quantitative relationship between the peak height and the carbon concentration has been derived. The energy of vacancy formation as well as the binding energy of the carbon pairs have been determined.