The monoclonal antibody,anti-asialoglycophorin from human erythrocytes,specific forβ-d-Gal-1-3-α-d-GalNAc-chains (Thomsen-Friedenreich receptors)

The monoclonal antibody 22.19 of IgM class obtained after immunization of BALB/c mice with asialoglycophorin of human erythrocyte membranes is described. The specificity of this antibody for -d-Gal-1-3--d-GalNAc- disaccharide chains (Thomsen-Friedenreich receptors) was established by studying its reactivity against various erythrocytes, glycoproteins and oligosaccharides and by comparison with two lectins, peanut agglutinin andVicia graminea lectin, which recognize these disaccharide chains.Abbreviations PNA peanut agglutinin - VgL Vicia graminea lectin - TF Thomsen-Friedenreich - HSA human serum albumin - MoAb monoclonal antibody     

Photogeneration of singlet oxygen (1O2) and free radicals (Sen·-, O·-2) by tetra-brominated hypocrellin B derivative

To improve photodynamic activity of the parent hypocrellin B (HB), a tetra-brominated HB derivative (compound 1) was synthesized in high yield. Compared with HB, compound 1 has enhanced red absorption and high molar extinction coefficients. The photodynamic action of compound 1, especially the generation mechanism and efficiencies of active species (Sen^·-, O^·-₂ and ¹O₂) were studied using electron paramagnetic resonance (EPR) and spectrophotometric methods. In the deoxygenated DMSO solution of compound 1, the semiquinone anion radical of compound 1 is photogenerated via the self-electron transfer between the excited and ground state species. The presence of electron donor significantly promotes the reduction of compound 1. When oxygen is present, superoxide anion radical (O^·-₂) is formed via the electron transfer from Sens^·- to the ground state molecular oxygen. The efficiencies of Sens^·- and O^·-₂ generation by compound 1 are about three and two times as much as that of HB, respectively. Singlet oxygen (¹O₂) can be produced via the energy transfer from triplet compound 1 to ground state oxygen molecules. The quantum yield of singlet oxygen (¹O₂) is 0.54 in CHCl₃ similar to that of HB. Furthermore, it was found that the accumulation of Sens^·- would replace that of O^·-₂ or ¹O₂ with the depletion of oxygen in the sealed system.     

О РАСЧЛЕНЕИИ НИЖНЕКАМЕННОУΓОЛЫХ ОТЛОЖЕНИЙ СЕВЕРНОΓО СКЛОНА ХРЕБТА БОРО-ХОРО(ВОСТОЧНАЯ ЧАСТЬ ТЯНЬ-ШАНЯ,СИНЬЦЗЯНЬ)

B KoHue习X eT助eT“月PyeeKH盆reo月OrMy二KeToB H.B.(1575一1900r,r.)BnePB曰e Bhl八即朋HH水HeKaMeHH0yro几bHbleor卫咪eHu分no eo6PaHH滩‘HM中ayHePa3Pe30B H3BeCTH只KOBB BePx阳b只x P.A川a几a“P.八水ePra几aH eeBePHoroCKJIOHa玩Po·XoPo. flos及HeegTOTPa仑oH noceTM卫H HeMe双KHe reo卫orH:MeP玖6axeP(1907一1909r。r。Merzbaeher),rPe6eP(Gr6ber,1908一1909 r.r.),KPeHKe几b(KreDkel,1913 r.).OHHBflePBble八aJIH onHCaHHeOT几。尧KeHH直.BH3e直cKO直中ayH乒H TeM caM曰M yToq…     

Structure of Poly (dT)·Poly (dA)·Poly (dT)

Abstract

The molecular structure of poly (dT)·poly (dA)·poly (dT) has been determined and refined using the continuous x-ray intensity data on layer lines in the diffraction pattern obtained from an oriented fiber of the DNA. The final R-value for the preferred structure is 0.29 significantly lower than that for plausible alternatives. The molecule forms a 12-fold right- handed triple-helix of pitch 38.4 Å and each base triplet is stabilized by a set of four Crick-Watson-Hoogsteen hydrogen bonds. The deoxyribose rings in all the three strands have C2′-endo conformations. The grooveless cylindrical shape of the triple-helix is consistent with the lack of lateral organization in the fiber.     

НОВЫЙ ВИД РОДА NOTOPYGOS(AMPHINOMID AE,POLYCHAETA)ИЗ ЮЖНО-КИТАЙСКОГО МОРЯ С ОСТРОВОВ СИШАЦЮНЬДАО(ПАРАСЕЛЬСКИЕ ОСТРОВА)

1956—58.     

Synthesis,characterization, and biological activity of Nα-(N-fluoresceinthiocarbamoyl)-(Asp1, Ile5)-angiotensin II

A fluorescent analog of angiotensin II was synthesized by reacting fluorescein 5′-isothiocyanate with (Asp¹, Ile⁵)-angiotensin II. N^α-(N-Fluoresceinthiocarbamoyl)-(Asp¹, Ile⁵)-angiotensin II was purified by chromatography on DEAE-cellulose and Sephadex G-25. Analysis of the analog by thin-layer chromatography, thin-layer electrophoresis, and reversed-phase high-performance liquid chromatography indicated that the analog was free of angiotensin II and fluorescein 5′-isothiocyanate. N-Terminal sequence analysis demonstrated that fluorescein 5′-isothiocyanate reacted with the N-terminal aspartic acid residue of angiotensin II. N^α-(N-Fluoresceinthiocarbamoyl)-(Asp¹, Ile⁵)-angiotensin II has an absorption maximum at 492 nm, and the value of the molar extinction coefficient, ?, is 7.7 × 10⁴m^?1 cm^?1. The fluorescence emission maximum occurs at 520 nm. Infusion of the analog (0.69 μg/min/kg body wt) directly into the renal artery of an anesthetized rat reduced the blood flow by 12 to 27% within 2 min. Infusion of angiotensin II (0.48 μg/min/kg body wt) reduced renal arterial blood flow by 35 to 53% within 2 min. Saralasin, a partial agonist and antagonist of angiotensin II, inhibited the biologic effect of the fluorescent analog and angiotensin II by 75 and 70%, respectively. The purity, spectral properties, and in vivo biologic activity of N^α-(N-fluoresceinthiocarbamoyl)-(Asp¹, Ile⁵)-angiotensin II indicate that this analog should facilitate characterization of angiotensin II receptors.     

Chemical analysis of new water-soluble (1→6)-, (1→4)-α, β-glucan and water-insoluble (1→3)-, (1→4)-β-glucan (Calocyban) from alkaline extract of an edible mushroom, Calocybe indica (Dudh Chattu)

Two different glucans (PS-I, water-soluble; and PS-II, water-insoluble) were isolated from the alkaline extract of fruit bodies of an edible mushroom Calocybe indica. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR analysis ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of these polysaccharides were established as: PS-I: →6)-β-D-Glcp-(1→6)-β-D-glcp-(1→6)-)-β-D-Glcp-(1→ α-D=Glcp (Water-soluble glucan). PS-II: →3)-β-D-Glcp-(1→3)-β-D-glcp-(1→3)-)-β-D-Glcp-(1→3)-β-D-Glcp-(1→ β-D-Glcp (Water-insoluble glucan, Calocyban).     

Structures for the polynucleotide complexes poly(dA) · poly(dT) and poly(dT) · poly(dA) · poly(dT)

X-ray diffraction analyses of fibers of polydeoxyadenylic acid · polydeoxythymidylic acid show that this molecule exists as a 10-fold double-helix with axial rise per nucleotide $\text{h = 3.24}\text{to}\text{3.29}\text{A}\text{?}$. The structure is very similar to B-DNA ($\text{h = 3.37}\text{A}\text{?}$) in having C3-exo furanose rings and base-pairs positioned centrally on the helix axis, but distinctive enough to have two packing modes, neither of which has been observed for B-DNA. Although the triple-stranded poly(dT) · poly(dA) · poly(dT) also has a large value of h(3.26 Å), each of the chains is a 12-fold helix of the A-genus with C3-endo furanose rings and bases displaced several Angstrom units from the helix axis.     

一种制备poly(Ⅰ)·poly(C)-滤纸的新方法

poly(1)·poly(C)-滤纸是一种亲和材料,可以用来吸附与双链核酸有亲和力的酶或蛋白。本文介绍用对-β硫酸酯乙砜基苯胺为活化剂制备poly(I)·poly(C)-滤纸的方法。poly(I)·poly(C)的结合容量为10—35μg/cm~2,用来吸附兔网织红细胞裂解液中2’-5’A合成酶效果良好。在一定范围内,酶活与被吸附裂解液量呈线性关系,说明可以用来定量检测未知样品中与poly(I)·poly(C)有亲和力的酶。poly(I)·poly(C)-滤纸在-20℃保存四个月亲和能力不变。本方法与文献报道的方法相比,操作简便试剂易得。     

Preparation of (±)-2-(2,3-2H2)Jasmonic Acid and Its Methyl Ester,Methyl (±)-2-(2,3-2H2)Jasmonate

For use as the internal standards in a quantitative analysis of natural jasmonic acid (JA) and methyl jasmonate (JAMe) by gas chromatography-mass spectrometry-selected ion monitoring, (±)-2-(2,3–²H₂)JA and its methyl ester, (±)-2-(2,3–²H₂)JAMe, were efficiently prepared from 2-(2–pentyl)-2-cyclopentenone through catalytic semi-deuteriogenation of acetylenic intermediates with deuterium gas in pyridine.     

The cooperativity between hydrogen and halogen bond in the XY···HNC···XY (X,Y = F,Cl, Br) complexes

The cooperativity between hydrogen and halogen bonds in XY···HNC···XY (X, Y = F, Cl, Br) complexes was studied at the MP2/aug-cc-pVTZ level. Two hydrogen-bonded dimers, five hydrogen-bonded dimers, and ten trimers were obtained. The hydrogen- and halogen-bonded interaction energies in the trimers were larger than those in the dimers, indicating that both the hydrogen bonding interaction and the halogen bonding interaction are enhanced. The binary halogen bonding interaction plays the most important role in the ternary system. The hydrogen donor molecule influences the magnitude of the halogen bonding interaction much more than the hydrogen bonding interaction in the trimers with respect to the dimers. Our calculations are consistent with the conclusion that the stronger noncovalent interaction has a bigger effect on the weaker one. The variation in the vibrational frequency in the HNC molecule was considered. The NH antisymmetry vibration frequency has a blue shift, whereas the symmetry vibration frequency has a red shift. A dipole moment enhancement is observed upon formation of the trimers. The variation in topological properties at bond critical points was obtained using the atoms in molecules method, and was consistent with the results of the interaction energy analysis.     

Effect of electro-acupuncture on ovarian expression of α (1)- and β (2)-adrenoceptors,and p75 neurotrophin receptors in rats with steroid-induced polycystic ovaries

Background  

Estradiol valerate (EV)-induced polycystic ovaries (PCO) in rats is associated with an increase in ovarian sympathetic outflow. Low-frequency (2 Hz) electro-acupuncture (EA) has been shown to modulate sympathetic markers as well as ovarian blood flow as a reflex response via the ovarian sympathetic nerves, in rats with EV-induced PCO.     

Synthesis,Protonation Behavior,Conformational Analysis,and Regioselective Enzymatic Acylation of the Novel Diamino Analogue of (E)-5-(2-Bromovinyl)-2′-deoxyuridine (BVDU)

Abstract

(E)-3′,5′-Diamino-5-(2-bromovinyl)-2′,3′,5′-trideoxyuridine (5), the diamino analogue of BVDU (1), was synthesized from BVDU. The protonation behavior of 5 has been studied by means of pH-metric measurements and NMR spectroscopy. This study allows the determination of the basicity constants and the stepwise protonation sites. Thus, the main species at physiological pH is the monoprotonated form. The conformational analysis of this nucleoside analogue was also carried out through ¹H NMR spectroscopy. In addition, a convenient synthesis of N-3′ and N-5′ acylated derivatives was developed by regioselective enzymatic acylation. Thus, Candida antarctica lipase B (CAL-B) selectively acylated the 5′-amino group, thus furnishing nucleosides 8. On the other hand, immobilized Pseudomonas cepacia lipase (PSL-C) exhibited the opposite selectivity, conferring acylation at the 3′-amino group, thus affording derivatives 9.     

Development and validation of competition binding assays for affinity to the extracellular matrix receptors, α(v)β(3) and α(IIb)β(3) integrin

The RGD (Arg-Gly-Asp) binding integrins α(v)β(3) and α(IIb)β(3) are integral components of various pathological and physiological processes, including tumor angiogenesis, osteoclast function, and thrombus formation. Because of this, there is interest in identifying novel compounds and proteins binding to these receptors as well as investigating the mechanism of these interactions. In this article, we describe the development and validation of competition binding assays for determining the affinity of test compounds to α(v)β(3) and α(IIb)β(3) integrin. Assays were successfully developed for each receptor, and the affinity of known compounds was comparable to published results. However, the inability of binding between α(IIb)β(3) integrin and the labeled echistatin protein ligand to reach equilibrium resulted in an assay that did not meet the assumptions of the competition binding model. Nevertheless, there was good agreement between this assay and known literature values, and intra- and interassay variability was acceptable. Binding by conformation-specific antibodies provided evidence that solid-phase bound α(IIb)β(3) receptor was in an activated conformation. This study also demonstrated that current models and methods for determining receptor affinity are simplistic and fail to account for common receptor-ligand interactions such as nondissociable interactions and varying receptor activation states.     

Probing β-(1→3)-D-glucans interactions with recombinant human receptors using high-resolution NMR studies

A full characterization of the high-resolution NMR spectrum of the laminarihexaose is described and used for the determination of the binding epitope of the more complex but structurally related laminarin. These biophysical data extend the current knowledge of β-glucans/Dectin-1 interactions and suggest different biological mechanisms in close relation with the size of the saccharidic chain.