Subunit composition, X-ray diffraction, amino acid analysis and oxygen binding behaviour of Panulirus interruptus hemocyanin

1975 ◽  
Vol 99 (4) ◽  
pp. 619-629 ◽  
Author(s):  
H.A. Kuiper ◽  
W. Gaastra ◽  
J.J. Beintema ◽  
E.F.J. van Bruggen ◽  
A.M.H. Schepman ◽  
...  
Author(s):  
Felix de Haas ◽  
Jan F. L. van Breemen ◽  
Martha M. C. Bijlholt ◽  
Ernst F. J. van Bruggen

Hemocyanin is a biological macromolecule which occurs freely dissolved in the hemolymph of certain invertebrates. The function of this copper containing protein is the transport of oxygen through the organism. In fulfilling this task hemocyanin has developed a similar mechanism as hemoglobin in binding oxygen reversibly and cooperatively. The hemocyanin of arthropods consists of one or more hexamers of subunits with a molecular weight of approx. 75 000. Depending on the species 3-15 types of monomeric subunits occur, which differ in amino-acid composition and in their oxygen binding properties. Each type of subunit fulfills a specific role in the architecture of that hemocyanin. In nature arthropodan hemocyanin is found as a one-hexameric, two-hexameric (dodecameric), four-hexameric or eight-hexameric molecular assembly depending on the species. In this work we focus on the difference in organization of the hexamers in the dodecamer of two different species i.e. the tarantula Eurypelma californicum (a chelicerate) and the crab Cancer pagurus (a crustacean). Eurypelma hemocyanin is made from 7 different subunits called a - g, whereas Cancer hemocyanin consists of 3 subunit types termed α, β, and γ .By image analysis of electron micrographs of the two-hexameric half hemocyanin molecules from Eurypelma and the two-hexameric whole hemocyanin molecules from Cancer, computer averaged projections of these dodecamers were obtained as shown in fig. 1. They differ clearly in their interhexameric contacts. To analyse this difference in more detail these projections were used as a reference in a simulation procedure.


1977 ◽  
Vol 73 (2) ◽  
pp. 311-321 ◽  
Author(s):  
W Herth ◽  
A Kuppel ◽  
E Schnepf

Ordered microfibrils are formed on the membrane of the cytoplasmic tail of the alga Poteriochromonas after attachment to a substrate. The ultrastructure of native and extracted stalk fibrils was studied with electron microscope methods. In addition, the structural polysaccharide was characterized by hydrolyses, separation of the monomers by thin-layer chromatography, gas-liquid chromatography and amino acid analysis, and by X-ray diffraction. The alkali-resistant fibrils yielded mostly glucosamine upon extensive hydrolysis, and showed X-ray diffraction patterns similar to those of fugal chitin. It is concluded that the resistant core of the fibrils is chitinous.


1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.


2018 ◽  
Vol 6 (2) ◽  
pp. 132
Author(s):  
Shuaibu Musa ◽  
S O. Idris ◽  
A D. Onu

The resulted complexes produced between Fe (III) and Co (II) with biological molecules like amino acids play an important role in human life. They can be used as bioactive compounds as well as in industries. Fe (III) and Co (II) complexes are synthesized with Alanine amino acid. The complexes were characterized by X-ray diffraction, magnetic suscetivility, elemental analysis (AAS), molar conductance, melting point, infrared and uv-visible spectrophotometry analyses. The elemental analyses were used to determine the chelation ratio, 1:3(metal: ligands) for iron (III) Alanine and 1:2 ratio for cobalt (II) Alanine. The molar conductivity of the complexes show that the complexes are not electrolytic in nature. The x-ray data suggest monoclinic crystal system for all the complexes with the exception of Co-alanine, which is hexagonal. The magnetic susceptivility and electronic spectra suggest the complexes are high spin with octahedral geometry.The complexes show enhance activity in comparable to the amino acid.  


1971 ◽  
Vol 19 (1) ◽  
pp. 1-15 ◽  
Author(s):  
M. HARADA ◽  
C. ISERSKY ◽  
P. CUATRECASAS ◽  
D. PAGE ◽  
H. A. BLADEN ◽  
...  

The morphology of the fibril of amyloid derived from different individuals is similar, but occasionally significant differences are noted. All human amyloid filaments have a "β-pleated sheet" conformation as revealed by x-ray diffraction, and those examined after orientation show a "cross-β" pattern. All amyloid fibril concentrates studied so far can be fractionated to obtain the major amyloid protein component(s) by sequential gel filtration with 5 M guanidine-HCl in 1 N acetic acid on Sepharose 4B and Sephadex G-100 or G-75 columns with the removal of over 28% of proteins representing minor constituents. The major amyloid protein(s) obtained from the spleen and/or liver of six patients is found to contain tryptophan, to be deficient in hydroxylysine and hydroxyproline and usually at least one commonly occurring amino acid and to have a high content of dicarboxylic acid and short chain amino acids and unreactive (blocked) NH2-terminal groups or aspartic acid-asparagine (Asx). However, the amyloid protein(s) from each individual differs from that of the others in molecular weight, in amino acid composition and in the presence or absence of specific tryptic peptides. Amyloid protein(s) from the liver and spleen of the same individual is identical. No chemical characteristics distinguish amyloid proteins derived from cases classified clinically as "primary" from those classified as "secondary." There is a striking chemical similarity between amyloid proteins and the NH2-terminal variable fragment of the light and heavy chain of immumoglobulin proteins.


Nature ◽  
1987 ◽  
Vol 328 (6125) ◽  
pp. 63-66 ◽  
Author(s):  
Sharon Grayer Wolf ◽  
Leslie Leiserowitz ◽  
Meir Lahav ◽  
Moshe Deutsch ◽  
Kristian Kjaer ◽  
...  

Clay Minerals ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 491-500 ◽  
Author(s):  
L. Fu ◽  
B. M. Weckhuysen ◽  
A. A. Verberckmoes ◽  
R. A. Schoonheydt

AbstractComplexes of Cu(lysine)2+2 and Cu(histidine)2+2 have been intercalated between the layers of saponite clays by a simple cation exchange procedure from aqueous solutions of preformed Cu(amino acid)2-complexes. Successful immobilization was obtained with an amino acid: Cu2+ ratio of 5, and a pH of 10 and 7.3 for lysine and histidine, respectively. The synthesized materials were investigated as powders and as thin films by electron spin resonance (ESR), diffuse reflectance spectroscopy (DRS) and X-ray diffraction (XRD). The light blue clays are characterized by an axially symmetric ESR spectrum with A//= 192 G, g//= 2.23 and g⊥ = 2.07, and a d-d absorption band around 600 nm, due to the intercalated planar Cu2+-complexes. Ammonia interacts reversibly with these intercalated complexes, suggesting the presence of a free coordination site. The novel synthesized materials are active in various oxidation reactions with t-butyl hydroperoxide as oxidant.


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