Polymorphism of minor histocompatibility genes in wild mice

H-2^b-restricted cytolytic T lymphocytes (CTL) were generated against H-1, H-3, and H-4 antigens and tested against target cells of F₁ hybrids between wild mice and inbred H-2 ^b mice. The congenic strain combinations for the CTL production were such that they tested one allele each at the H-1 and H-4 loci and four alleles at the H-3 locus. Most of the wild mice tested came from Southern Germany, but a few mice came from other European countries and Egypt and Israel. Virtually all wild mice typed as positive with CTL directed against H-3^b and H-4^b antigens; 32% of the F₁ hybrids tested reacted with anti-H-1^cCTL and 9% reacted with anti-H-3^d CTL. The positive results were not caused by cross-reaction with allogeneic H-2 antigens controlled by the major histocompatibility complex (Mhc) genes of the wild mice. At least some of the H-3 and H-4 antigens detected by the CTL in the F₁ hybrid were not identical with antigens of the immunizing strains. These results suggest a relatively low degree of polymorphism of the tested minor H loci in wild mice and further support the notion that minor H loci are unrelated to the Mhc.     

Purification of H-2a heavy chain and beta-microglobulin by reverse-phase high-performance liquid chromatography

Partially purified, papain-solubilized H-2^a histocompatibility antigens from $\text{A}\text{J}$ mouse liver have been purified by reverse-phase high-performance liquid chromatography using RP-18 columns. β₂-Microglobulin and H-2^a heavy chain were separated from each other, without reduction or carboxymethylation, in less than 30 min by elution with a linear gradient of ethanol in 12 mm HCl. As much as 5 mg of protein has been loaded at a time. The recovery of the proteins from the RP-18 columns was estimated to be approximately 35% for the H-2^a heavy chain and 80% for β₂-microglobulin.     

The further investigation of physical and photochemical properties of quasimetacyclophane derived from thymine

The thymine derived quasimetacyclophane exist in two conformers $\text{a}$ and $\text{b}$. The absorption spectra of $\text{a}$ and $\text{b}$ were evaluated and the conformational equilibrium in different solvents /H₂O : EtOH/ were examined. The rate constant k_?1 for reaction $\text{b}\text{→}\text{a}$ was established as well as E_a.     

Trichinella spiralis: genetic basis for differential expression of phase-specific intestinal immunity in inbred mice

Responsiveness of mouse strains after phase-specific immunization with Trichinella spiralis is compared. Two strains ($\text{NFR}\text{N, NFS/N}$) showed strong overall responsiveness. The response type could be characterized in phase-specific terms as: strongly anti-adult, weakly to moderately anti-preadult, and strongly antifecundity. By comparison, congenic mice of the C₅₇B1 $\text{10}\text{Sn}$ background (B10·A, B10·D₂, B10·S, B10·Q) displayed poor total responses that could be characterized as: weakly anti-adult, very weakly anti-preadult, weakly anti-fecundity after preadult immunization, and mixed (weak and strong) after adult immunization. The $\text{C}{}_3\text{H}\text{HeJ}$ mouse appeared to be intermediate between the B10·BR and the $\text{NFR}\text{N}$ strains in overall responsiveness. Genetic determinants of anti-preadult or anti-adult responses of $\text{NFR}\text{N}$ strain mice were dominant over their B10 congenic counterparts as shown in F₁, crosses of $\text{NFR}\text{N}$ × B1O·BR mice. Since the $\text{NFR}\text{N}$ (predominantly H-2^q) and the $\text{NFS}\text{N}$ (H-2^S) are both strong responders, while the B10·Q(H-2^q) and B10·S (H-2^S) are weak, it is suggested that the major genes controlling anti-preadult and anti-adult responses are not linked to the major histocompatibility complex. However, variations in anti-adult immunity and anti-fecundity in the B10 congenic mice (B10·Q and B10·S are the strongest responders) suggest that minor genes linked to the MHC exert some control over these responses. Some evidence was obtained for gene complementation as the F₁ cross of $\text{NFR}\text{N}$ and $\text{NFS}\text{N}$ mice responded more vigorously than the parental lines. We conclude that multiple genes determine anti-T. spiralis intestinal responses in mice. The major genes are unlinked to the major histocompatibility complex whereas several minor genes are linked.     

Synthesis and antitumor activity of platinum complexes of protonated diamines

Complexes of the formula cis-[Pt(H$\text{N}\text{+}$^～N)(L)Cl₂], where (H$\text{N}\text{+}$^～N) are the protonated diamines including 3-aminoquinuclidine, N-aminopiperidine, piperazine, N-methylpiperazine, 1,1,4-trimethylpiperazine, and N-methyl-1,4-diazabicyclo [2,2,2] octane (N-methyl-dabco) and L = SCN^?, NO₂^?, Br^?, and F^?, were synthesized from the protonated diamine complexes, [Pt(H$\text{N}\text{+}$^～N)Cl₃]. The antitumor activities of the complexes were evaluated in vitro against L1210 murine leukemia cells, and ID₅₀ values for the L-substituted complexes were compared to values of the parent complexes. In each case it was found that replacement of a chloride ion by SCN^?, NO₂^?, Br^?, or F^?, either reduced or completely eliminated antitumor activity. This effect is explained in terms of the trans-directing ability of the ligand, L, compared to chloride. The NO₂-substituted complex of 3- aminoquinuclidine was tested in vivo and found to exhibit little or no antitumor activity.     

Variance of actual inbreeding

The variances of actual inbreeding and coancestry in terms of their corresponding identities by descent were studied for finite populations. For inbreeding at a single locus, the total variance σ² = F(1 ? F) (F is the inbreeding coefficient) is comprised of a component σ_w² within populations and a component σ_b² between replicate populations. These variances increase in time to a maximum at about 1.1N_e generations for σ_w², about 2.3N_e generations for σ_b², and about 1.4N_e generations for σ², and decrease thereafter (N_e is effective population size). The ratio $\text{σ}{}_{\mathrm{<mtext>b</mtext>}}{}^2\text{σ}{}^2$ is ever increasing to an asymptote in the range 0.4-0.5 depending on N_e and the mating system. For finite populations with variation in pedigree F's, there are contributions σ_wF² within and σ_bF² between populations. The component σ_bF² is insignificant except for very small populations, and σ_wF² is largest in the early generations and then decreases roughly as $\text{(1 ? F)}{}^2\text{KN}{}_{\mathrm{<mtext>e</mtext>}}\text{where}\text{K}$ is formulated in terms of the mating strategy and the degree of avoidance of mating relatives. An additional degree of avoidance increases K by a factor of 4. In a large population at equilibrium with respect to mixed self and random mating, σ_wF² accounts for onehalf to two-thirds of σ_w². Bringing in more loci leads to the decomposition of the total variance into four components whose values are affected by linkages among the loci. The relationships between these components and σ_w², σ_b², σ_wF², and σ_bF², are elaborated in terms of tight and loose linkage. The exact computations of σ_wF² and σ_bF² require the use of two locus descent measures without linkage. The variances of various averages of actual identities by descent, such as the proportions for individuals or populations, are formulated for a sample of individuals.     

Production of anti-self-H-2 antibodies by C3D2F1 mice hyperimmune to L cell/L1210 hybrids and L1210 leukemia cells

During the course of immunization of (C3H × DBA/2)F₁ mice (genotype H-2^k/b) with L cell (H-2^k/k)/L1210 leukemia cell (H-2^d/d) hybrids and L1210 leukemia cells, some of them produced a good titer of anti-self-H-2 (H-2^d) antibodies. Antigens recognized by this anti-self-H-2 antiserum were shown to be controlled by the H-2K-IA-IB-IJ-IE subregions of the H-2^d but not H-2^k nor H-2^b haplotypes of parental as well as F₁ origins and to have a tissue distribution identical to that of class 1 H-2 (H-2K/D) antigens.     

Antenna function of a chlorophyll ab protein complex of Photosystem I

The functional role of a chlorophyll $\text{a}\text{b}$ complex associated with Photosystem I (PS I) has been studied. The rate constant for P-700 photooxidation, K_P-700, which under light-limiting conditions is directly proportional to the size of the functional light-harvesting antenna, has been measured in two PS I preparations, one of which contains the chlorophyll $\text{a}\text{b}$ complex and the other lacking the complex. K_P-700 for the former preparation is half of that of the preparation which has the chlorophyll $\text{a}\text{b}$ complex present. This difference reflects a decrease in the functional light-harvesting antenna in the PS I complex devoid of the chlorophyll $\text{a}\text{b}$ complex. Experiments involving reconstitution of the chlorophyll $\text{a}\text{b}$ complex with the antenna-depleted PS I preparation indicate a substantial recovery of the K_P-700 rate. These results demonstrate that the chlorophyll $\text{a}\text{b}$ complex functions as a light-harvesting antenna in PS I.     

Coordination chemistry of lanthanides with cryptands. An X-ray and spectroscopic study of the complex Nd2(NO3)6 [C18H36O6N2]·H2O

By reacting neodymium nitrate hexahydrate with the cryptand 〈222〉 in methanol, the complex Nd₂-(NO₃)₆[C₁₈H₃₆O₆N₂]·H₂O was obtained and analyzed by single-crystal X-ray diffraction. The cell is triclinic P$\text{1}$ with a = 14.870(2) Å, b = 13.261(2) Å, c = 8.832(1) Å, α = 91.2(1)°, β = 93.4(1)°, γ = 87.6(1)°, Z = 2 and U = 1736.6 ų. The structure was refined by least-squares methods to the conventional R = 0.039 for 6177 observed reflections. The compound contains the cations [Nd〈222〉(NO₃)]²⁺ and the anions [Nd(NO₃)₅·H₂O]^2?, and is isostructural with the samarium analogue. Solid state fluorescence spectra of the title complex were measured at room and liquid nitrogen temperature, and the transitions ⁴F_3/2 → ⁴I_9/2 and ⁴F_3/2 → ⁴I_11/2 analyzed.     

Chlorophyll-protein complexes of a Codium species,including a light-harvesting siphonaxanthin-Chlorophylla ab-protein complex,an evolutionary relic of some Chlorophyta

Eight chlorophyll-protein complexes were isolated from thylakoid membranes of a Codium species, a marine green alga, by mild SDS-polyacrylamide gel electrophoresis. CP 1a¹, CP 1a², CP 1a³ and CP 1a⁴ were partially dissociated Photosystem (PS) I complexes, which in addition to the core reaction centre complex, CP 1, possessed PS I light-harvesting complexes containing chlorophyll (Chl) a, Chl b and siphonaxanthin. LHCP¹ and LHCP³ are orange-brown green chlorophyll $\text{a}\text{b-}\text{proteins}$ ($\text{Chl}\text{a}\text{Chl}\text{b}$ ratios of 0.66) that contain siphonaxanthin and its esterified form, siphonein. CP a and CP 1, the core reaction centre complexes of PS II and PS I, respectively, had similar spectral properties to those isolated from other algae or higher plants. These P-680- or P-700-Chl a-proteins are universally distributed among algae and terrestrial plants; they appear to be highly conserved and have undergone little evolutionary adaptation. Siphonaxanthin and siphonein which are present in the Codium light-harvesting complexes of PS II and PS I are responsible for enhanced absorption in the green region (518 and 538 nm). Efficient energy transfer from both xanthophylls and Chl b to only Chl a in Codium light-harvesting complexes, which have identical fluorescence emission spectra at 77 K to those of the lutein-Chl $\text{a}\text{b-}\text{proteins}$ ($\text{Chl}\text{a}\text{Chl}\text{b}$ ratios of 1.2) of most green algae and all higher plants, proved that the molecular arrangement of these light-harvesting pigments was maintained in the isolated Codium complexes. The siphonaxanthin-Chl $\text{a}\text{b-}\text{proteins}$ allow enhanced absorption of blue-green and green light, the predominant light available in deep ocean waters or shaded subtidal marine habitats. Since there is a variable distribution of lutein, siphonaxanthin and siphonein in marine green algae and siphonaxanthin is found in very ancient algae, these novel siphonein-siphonaxanthin-Chl $\text{a}\text{b-}\text{proteins}$ may be ancient light-harvesting complexes which were evolved in deep water algae.     

The reconstitution of a Photosystem II protein complex, P-700-chlorophyll a-protein complex and light-harvesting chlorophyll ab-protein

A Photosystem II reaction centre protein complex was extracted from spinach chloroplasts using digitonin. This complex showed (i) high rates of dichloroindophenol and ferricyanide reduction in the presence of suitable donors, (ii) low-temperature fluorescence at 685 nm with a variable shoulder at 695 nm which increased as the complex aggregated due to depletion of digitonin and (iii) four major polypeptides of 47, 39, 31 and 6 kDa on dissociating polyacrylamide gels. The Photosystem II protein complex, together woth the P-700-chlorophylla protein complex and light-harvesting chlorophyll $\text{a}\text{b-}\text{protein}$ complex (LHCP) also isolated using digitonin, were reconstituted with lipids from spinach chloroplasts to form proteoliposomes. The low-temperature (77 K) fluorescence properties of the various proteoliposomes were analysed. The $\text{F}{}_{685}\text{F}{}_{695}$ ratios of the Photosystem II reaction centre protein complex-liposomes decreased as the lipid to protein ratios were increased. The $\text{F}{}_{681}\text{F}{}_{697}$ ratios of LHCP-liposomes were found to behave similarly. Light excitation of chlorophyll b at 475 nm stimulated emission from both the Photosystem II protein complex (F₆₈₅ and F₆₉₅) and the P-700-chlorophyll a-protein complex (F₇₃₅) when LHCP was reconstituted with either of these complexes, demonstrating energy transfer between LHCP and PS I or II complexes in liposomes. No evidence was found for energy transfer from the PS II complex to the P-700-chlorophyll a-protein complex reconstituted in the same proteoliposome preparation. Proteoliposome preparations containing all three chlorophyll-protein complexes showed fluorescence emission at 685, 700 and 735 nm.     

Analysis of chlorophyll fluorescence induction curves in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea as a function of magnesium concentration and NADPH-activated light-harvesting chlorophyll ab-protein phosphorylation

The effect of Mg²⁺ concentration and phosphorylation of light-harvesting chlorophyll $\text{a}\text{b-}\text{protein}$ on various chlorophyll fluorescence induction parameters of isolated pea thylakoids has been studied. (1) Lowering the Mg²⁺ concentration from 3 to 0.4 mM decreases only the variable fluorescence (F_v) and the area above the induction curve while at the same time increasing the slow exponential component of the rise (β_max). (2) A further decrease in Mg²⁺ concentration from 0.4 to 0 mM decreases the initial (F₀) fluorescence level such that the ratio $\text{F}{}_{\mathrm{<mtext>v</mtext>}}\text{F}{}_{\mathrm{<mtext>m</mtext>}}$ increases slightly as does the area above the induction curve and β_max. (3) Thylakoid membranes, phosphorylated at 5 mM Mg²⁺, show an equal decrease in F_v and F₀, no change in the area above the induction curve and an increase in β_max. At 2 mM Mg²⁺, however, phosphorylation induced a more extensive quenching of F_v so that the $\text{F}{}_{\mathrm{<mtext>v</mtext>}}\text{F}{}_{\mathrm{<mtext>m</mtext>}}$ ratio was lowered and the area above the induction curve decreased while β_max increased. (4) When phosphorylated membranes were subsequently suspended in an Mg²⁺-free medium the effect on F₀ due to phosphorylation was found to be additive to that due to the absence of Mg²⁺. The effect of membrane phosphorylation on fluorescence is discussed in relation to the control of excitation energy distribution and shows that different mechanisms operate depending on the background Mg²⁺ levels. At high Mg²⁺ the phosphorylation seems to affect the absorption cross-section of Photosystem II while at lower Mg²⁺ levels there is an additional effect of increased spillover from Photosystem II to I.     

H-2-associated differences in androgen-influenced organ weights of a and C57BL/10 mouse strains and their crosses

The influence ofH-2 haplotypes (in three-month-old males) on body weight, vesicular gland, testes, and thymus weight was investigated in A, B10, and B10.A strains and their respective F₁, F₂, and Bc progeny. The influence of theH-2 haplotypes was found to contribute to heterosis in the body weight.H-2 ^a/H-2 ^a males have a smaller vesicular gland and larger testes and thymus weight thanH-2 ^b/H-2 ^b males when groups with an identical or comparable genetic background are compared.H-2 heterozygous classes are closer to the parental strain with higher values for absolute organ weight; for relative organ weight, the heterozygous classes are intermediate or closer to the parental strain with lower values. This complex situation results from the simultaneous action ofH-2 haplotypes on both organ weight (Hom-1 effect) and body weight (heterosis), which probably operate through different mechanisms. Coat color genes were found to modify the penetrance ofH-2 influence on quantitative traits.     

The nature of the light-harvesting complex as defined by sodium dodecyl sulfate polyacrylamide gel electrophoresis

Reelectrophoresis of the oligomer form (CP II1) of the chlorophyll $\text{a}\text{b}$ light-harvesting complex (LHC) from the green alga Acetabularia yields two green bands which run at the position typical of the monomer (CP II). The upper green band (CP II₁) is enriched in the 27 kDa polypeptide of the LHC, while the lower is enriched in the 26 kDa polypeptide. The fact that both bands have both chlorophyll (Chl) a and b, and in the same ratio, implies that the LHC is made up of two Chl $\text{a}\text{b}$ proteins. Neither of these bands can be attributed to the Chl $\text{a}\text{b}$ complex ‘CP 29’ (Camm, E.L. and Green, B.R. (1980) Plant Physiol. 66, 428–432). Resolution of CP II₁ and CP II₂ of spinach can be obtained if sucrose gradient fractions of an octylglucoside extract are subjected to SDS-polyacrylamide gel electrophoresis. CP II₁ and CP II₂ are interpreted as being fundamental subunits of the light-harvesting complex as it is defined on SDS-polyacrylamide gels.     

On the mechanism of the reaction of tris(hydroxymethyl)aminomethane with activated carbonyl compounds: A model for the serine proteinases

The pH dependence of the reaction of tris(hydroxymethyl)aminomethane (Tris) with the activated carbonyl compound 4-trans-benzylidene-2-phenyloxazolin-5-one (I) is given by the equation $\text{k′}{}_2\text{=}\text{k}{}_{\mathrm{<mtext>b</mtext>}}\text{K}{}_{\mathrm{<mtext>a</mtext>}}\text{(K}{}_{\mathrm{<mtext>a</mtext>}}\text{+ [}\text{H}{}^{\mathrm{+}}\text{])}\text{+}\text{k}{}_{\mathrm{<mtext>a</mtext>}}\text{[}\text{OH}{}^{\mathrm{?}}\text{]K}{}_{\mathrm{<mtext>a</mtext>}}\text{(K}{}_{\mathrm{<mtext>a</mtext>}}\text{+ [}\text{H}{}^{\mathrm{+}}\text{])}$, where K_a is the dissociation constant of TrisH⁺. Spectrophotometric experiments show that the Tris ester of α-benzamido-trans-cinnamic acid is formed quantitatively over a range of pH values, regardless of the relative contribution of k_b and k_a terms to k′₂. Hence, both terms refer to alcoholysis. While the mechanism of the reaction is not determined unequivocally in the present work, the magnitude of the k_b term, together with its dependence on the basic form of Tris, suggests that ester formation is occurring by nucleophilic attack of a Tris hydroxyl group on the carbonyl carbon of the oxazolinone, with intramolecular catalysis by the Tris amino group. The rate enhancement due to this group is at least 10² and possibly of the order 10⁶. This system is compared with other model systems for the acylation step of catalysis by serine esterases and proteinases.     

Control of the antibody response of C57BL/6 Lyt-congenic strains to the Lyt-3.1 alloantigen by a gene linked to theLyt-2 locus

Congenic anti-Lyt-3.1 sera have recently been produced by immunizing B6-Lyt-2^a mice with thymocytes from either B6-Lyt-2^a, Lyt-3^a or B6-Lyt-2^a, Lyt-3^a, H-2^k mice (Boos et al. 1978). Surprisingly, mice of the congenic strain B6 failed to produce either anti-Lyt-2.1 or anti-Lyt-3.1 cytotoxic antibodies after identical immunizations. To determine the genetic basis for the difference in response to Lyt-3.1, (B6 × B6-Lyt-2^a)F_a mice and progeny of the backcross, (B6 × B6-Lyt-2^a)F₁ × B6-Lyt-2^a, were immunized with B6-Lyt-2^a, Lyt-3^a, H-2^k thymocytes. In addition, thymic biopsies of backcross progeny were performed and thymocytes tested for the Lyt-2.2 antigenic specificity. Results indicate that gene(s) governing the immune response to Lyt-3.1 is (are) linked to theLyt-2 locus, and that the responder allele (linked toLyt-2 ^a ) shows very poor penetrance in Lyt-2^a/Lyt-2^b mice.