The globulins of cotton seeds X. Structures of tryptic peptides of the 7S globulin

Summary The amino-acid sequences of the tryptic peptides of the 7S globulin of cotton seeds have been determined.An analysis of the peptides obtained has been performed and on the basis of the overlapping chymotryptic peptides the sequence of tryptic peptides in the chain of the 7S globulin has been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 679–682, September–October, 1977.     

The globulins of cotton seeds XI. The structure of the chymotryptic peptides of the 7S globulin

Summary The amino-acid sequences of the chymotryptic peptides of the 7S globulin of cotton seeds have been determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 682–687, September–October, 1977.     

Denaturation and renaturation of the 11S globulin of cotton seeds by polarography

It has been established by a polarographic analysis of the globulins of cotton seeds that the 7S and 11S golublins possess a two-step polarographic wave with a half-wave potential of –1.42 V. On the basis of the results of a study of the kinetics of thermal denaturation the high lability of the 11S globulin on heating has been shown. The conditions have been determined of the complete denaturation of the 11S globulin in 8 M urea solution and it has been established that the latter is an irreversible process.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 809–813, November–December, 1980.     

The change in the globulins during the development of cotton seeds

The biosynthesis of the 11S and 7S globulins — the main reserve proteins of cotton seeds — has been investigated. The periods at which the globulins appear in cotton seeds have been established. The changes in the amino acid composition and in the secondary structure of the 11S globulin during the ripening of cotton seeds have been studied.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Molecular Biology, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–355, May–June, 1984.     

An investigation of the globulins of cotton seeds. IV

Summary 1. A method has been developed for the preparative separation of the subunits of the 7S globulin of cotton seeds.2. The similarity of the chemical structures of the subunits has been shown by the peptide map method and by a comparison of amino-acid compositions and of N- and C-terminal amino acids. It is suggested that their main difference consists in their carbohydrate contents.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 229–233, March–April, 1976.     

A study of the globulin of cottonseeds. XXIV. Isolation and characterization of a glycopeptide of the 7S globulin

From a pronase hydrolysate of the 7S globulin of cottonseeds, using a column containing Sephadex G-25 and paper chromatography, a glycopeptide has been isolated which contains in its molecule residues of aspartic acid, glucosamine, and mannose in a ratio of 1:2:5. It has been shown by an analysis of the products of the methylation of the glycopeptide that the carbohydrate chain has a branched structure.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 215–217, March–April, 1981.     

Modification of the reserve proteins during the germination of cotton seeds

The hydrolysis of the 11S globulin begins in the early stages of the germination of cotton seeds and is complete during the first 4–5 days. During the first 3 days, only limited hydrolysis of the reserve protein takes place, and only on the 4th day does it undergo far-reaching hydrolysis, after which the protein cannot be detected either by immunochemical methods or by electrophoresis and analytical ultracentrifugation.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbekistan Republic, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 443–445, 447, May–June, 1993.     

The globulins of cotton seeds XIX. Chymotryptic and tryptic peptides of subunit C of the 11S globulin

Summary 1. The structures of 51 chymotryptic peptides isolated from a chymotryptic hydrolyzate of subunit C have been determined.2. The structures of 15 tryptic peptides from a tryptic hydrolyzate of subunit C have been established.3. On the basis of the structures of the peptides, the structure of the molecule of subunit C of the 11S globulin of cotton seeds has been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 613–621, September–October, 1978.     

Primary structure of subunit B of the 11S globulin of cotton seeds of variety 108-F. VI. Reconstruction of the polypeptide chain

Subunit B of the 11S globulin of cotton seeds, the polypeptide chain of which contains about 190 amino acid residues, has been reconstructed on the basis of large fragments from three types of tryptic hydrolyses.Institute of the Chemistry of Plant Substances, Academy of Science of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 230–233, March–April, 1984.     

Primary structure of subunit B of the 11S globulin of seeds of cotton plant variety 108-F. I. Acid-soluble peptides from complete tryptic hydrolysis of subunit B

The 11S globulin of cotton seeds consists of three types of subunits: A, B, and C. The complete tryptic hydrolysis of subunit B has given acid-soluble and acid-in-soluble peptides. The amino acid compositions and amino acid sequences of the acid-soluble peptides have been determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 88–93, January–February, 1984.     

A study of the 11S globulin from cotton seeds IX. Structure of the glycopeptide

Summary 1. The oligosaccharide of the glycopeptide (I) from subunit C of the 11S globulin of cotton seeds consists of one molecule of glucosamine and three molecules of mannose.2. The oligosaccharide is attached to the protein through the glucosamine and has a branched structure.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 675–678, September–October, 1977.     

Surface characterization of 7S and 11S globulin powders from soy protein examined by X-ray photoelectron spectroscopy and scanning electron microscopy

In this study the surface composition of 7S and 11S globulin powders from soybean proteins by aqueous buffer and reverse micelle extractions had been examined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Analysis by XPS revealed that the O and N atomic percentage of 7S and 11S globulin surfaces from bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelle was higher than from aqueous buffer, but the C atomic percentage was lower. The O/C ratio of the 7S globulin powder from aqueous buffer and reverse micelle was similar while significant differences were obtained in the O/C ratio of the 11S globulin powder, N/C atom ratios of the 7S and 11S globulin powders and high-resolution XPS C 1s, N 1s, O 1s spectra. Powder microstructure after reverse micelle treatment showed the presence of small pores, indicating the effect of reverse micelle on the 7S and 11S globulin structure. The obtained results indicated that the reverse micelle could affect the C, O and N components on the surface of soybean proteins.     

The nature of the globulin of the algaPhyllophora nervosa

Conclusions The globulin of the algaPhyllophora is heterogeneous and consists of a number of fractions, some of which we assign to the glycoproteins. These fractions differ in their molecular weights, N-terminal amino acids, and the amount and composition of the amino acids and carbohydrates.The main difference between the fractions ofPhyllophora globulin is the nature of the carbohydrate bond with the true protein part of the molecule.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 3, pp. 351–355, 1970     

Absolute configuration of vinerine and vineridine

Summary On the basis of an analysis of the circular dichroism and NMR spectra the absolute configuration 7R, 3R, 4S, 15S, 19S, 20S has been established for vinerine; 7S, 3R, 4S, 15S, 19S, 20S for vineridine; and 7S, 3S, 4R, 15S, 19S, 20S for N-acetylvinerine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 493–502, July–August, 1974.     

An investigation of the globulins of cotton seeds. I

Summary 1. Cotton seeds contain five globulin components, two of which are the main representatives; the molecular weights of the latter are 130,000 and more than 300,000.2. The globulin with a molecular weight of 130,000 (N-terminal amino acid arginine) has a quaternary structure: it consists of two types of polypeptide chains.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 404–409, May–June, 1975.     

Voltammetric immunoassay of human albumin and goat antiserum to human albumin by nickel labeling

Summary Homogeneous und heterogeneous (in which globulin proteins were precipitated) voltammetric immunoassay (VIA) of nickel labeled human albumin was studied by monitoring the change in reduction currents of the metal protein complex. The concentration of human albumin nickel complex can be used to determine antiserum concentrations via immunochemical reaction. Concentration levels as low as 5.3×10^–7M goat antiserum to human albumin were measured using homogeneous VIA, and 3.3×10^–7 M using heterogeneous VIA and continuous flow analysis.

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Voltammetrische Immunoassay von Humanalbumin and Ziegenantiserum gegen Humanalbumin durch Nickelmarkierung

Zusammenfassung Ein homogener und ein heterogener (Fällung der Globulinproteine) voltammetrischer Immunoassay (VIA) von Nickelmarkiertem Humanalbumin wurde durch Messung der Änderung der Reduktionsströme des Metallproteinkomplexes untersucht. Die Konzentration des Humanalbumin-Nickelkomplexes kann zur Bestimmung von Antiserumkonzentrationen über eine immunochemische Reaktion benutzt werden. Konzentrationen bis herab zu 5,3·10^–7M Ziegenantiserum gegen Humanalbumin wurden mit dem homogenen VIA bestimmt, bis zu 3,3·10^–7M mit dem heterogenen VIA in Form der Durchflußanalyse.

     

Oxidative transformations of cembrane diterpenoids III. Epoxycembrenes

Summary 1. It has been established that the epoxidation of cembrene with perbenzoic and peracetic acids takes place stereospecifically at each of the trisubstituted double bonds with the formation of 4S,5R-, 7S,8S-, and 11S,12S-monoepoxycembrenes, the structures and absolute configurations of which have been established by spectral methods.2. Epoxidation of cembrene at the C₁₁–C₁₂ double bonds under the conditions used takes place preferentially as compared with epoxidation at the C₇–C₈ double bond.Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Novosibirsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 525–531, July–August, 1977.     

Voltammetric immunoassay of human albumin and goat antiserum to human albumin by cobalt labelling

Summary Homogeneous and heterogeneous voltammetric immunoassay (VIA) of human albumin and goat antiserum to human albumin were studied by monitoring the current of complexed cobalt and the Brdicka wave at the appropriate potentials as a function of immunochemical reaction using differential pulse polarography. Using homogeneous VIA, concentration levels as low as 2.0×10^–6 M human albumin and 1.1×10^–6M goat antiserum to human albumin showed detectable change in the observed currents. With heterogeneous VIA, in which globulin proteins were removed by precipitation, levels of human albumin as low as 1.0×10^–7M were detected.

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Untersuchung eines voltammetrischen Immunoassays für menschliches Albumin und Ziegenantiserum gegen menschliches Albumin durch Cobaltmarkierung

Zusammenfassung Ein homogener und ein heterogener voltammetrischer Immunoassay (VIA) wurde mit Hilfe der Differential-Pulspolarographie untersucht durch Messung des Stromes des komplexierten Cobalts und der Brdicka-Stufe bei dem entsprechenden Potential als Funktion der immunchemischen Reaktion. Mit dem homogenen VIA zeigten Konzentrationen von 2,0×10^–6 M von menschlichem Albumin und 1,1×10^–6M von Ziegenantiserum gegen menschliches Albumin noch erkennbare Stromänderungen. Mit dem heterogenen VIA (bei dem Globulinproteine durch Ausfällung entfernt wurden) konnten noch Konzentrationen von 1,0×10^–7 nachgewiesen werden.

     

Spin–orbit coupling in oxygen containing diradicals

Intermediate diradicals which occur in the Paterno–Büchi photocycloaddition and in the Norrish type I photoreactions have been calculated taking into account the spin–orbit coupling (SOC) between the singlet (S) and triplet (T) states. Reaction paths for the photocycloaddition of formaldehyde to ethene and the diradical products of the α-cleavage of cyclohexanone have been optimized by the MNDO CI method for a number of different singlet and triplet states. SOC integrals are calculated by an effective one-electron approximation. Intermediate diradicals in the Paterno–Büchi reaction and the SOC effects are also studied ab initio with CAS SCF geometry optimization in a TZV basis set. Both methods predict a large SOC matrix element between the S and T states in the course of the C–C attack, while the SOC integral is two orders of magnitude smaller for the diradical produced in the C–O attack. In the Norrish type I photoreaction the oxygen atom also produces some nonzero contribution to the SOC integral which governs intersystem crossing in a ·C–C· diradical. For the diradicals produced by the α-cleavage of cyclohexanone a vibronic interaction is responsible for the SOC mixing between the lowest S and T states. The importance of one-center versus two-center SOC contributions in diradicals is briefly discussed.     

Analysis of the Amino Acids of Soy Globulins by AOT Reverse Micelles and Aqueous Buffer

The 7S and 11S globulins from soybean proteins using reverse micelle and aqueous buffer extraction methods were characterized by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscope (SEM), and their amino acid compositions were also evaluated. SDS-PAGE did not show electrophoretic differences between 7S and 11S globulin subunits with two extraction methods. SEM analysis showed that the AOT reverse micelle processing of 7S and 11S globulins induced a reduction of droplet size. Some individual amino acid contents of 7S and 11S globulins using two extraction methods were different, some were similar. In all the samples, the glutamic acid, aspartic acid, and leucine were the dominant amino acids while the cystine and methionine were the first-limiting amino acids. The proportion of essential amino acids to the total amino acids (E/T) of the 7S globulin from aqueous buffer and reverse micelles was similar. While significant differences were obtained in the proportion of E/T of the 11S globulin.