scholarly journals Biochemical characterization of crystals from the dermal iridophores of a chameleon Anolis carolinensis.

1975 ◽  
Vol 66 (3) ◽  
pp. 635-645 ◽  
Author(s):  
S T Rohrlich ◽  
R W Rubin

The biochemical characteristics of dermal iridophore crystals from Anolis carolinensis have been investigated. Iridophores isolated by collangenase-hyaluronidase treatment were sonicated and their contents fractionated through sucrose. Pure iridophore crystals so obtained were examined by chromatography and electron diffraction. They were found to be pure hydrated crystalline form. The suggestion is made that the subcrystalline structure of this guanine does not play a role in color production by the iridophore.

2015 ◽  
Vol 198 (3) ◽  
pp. 544-552 ◽  
Author(s):  
Manuel Osorio-Valeriano ◽  
Javier de la Mora ◽  
Laura Camarena ◽  
Georges Dreyfus

ABSTRACTThe flagellar basal body is a rotary motor that spans the cytoplasmic and outer membranes. The rod is a drive shaft that transmits torque generated by the motor through the hook to the filament that propels the bacterial cell. The assembly and structure of the rod are poorly understood. In a first attempt to characterize this structure in the alphaproteobacteriumRhodobacter sphaeroides, we overexpressed and purified FliE and the four related rod proteins (FlgB, FlgC, FlgF, and FlgG), and we analyzed their ability to form homo-oligomers. We found that highly purified preparations of these proteins formed high-molecular-mass oligomers that tended to dissociate in the presence of NaCl. As predicted byin silicomodeling, the four rod proteins share architectural features. Using affinity blotting, we detected the heteromeric interactions between these proteins. In addition, we observed that deletion of the N- and C-terminal regions of FlgF and FlgG severely affected heteromeric but not homomeric interactions. On the basis of our findings, we propose a model of rod assembly in this bacterium.IMPORTANCEDespite the considerable amount of research on the structure and assembly of other flagellar axial structures that has been conducted, the rod has been barely studied. An analysis of the biochemical characteristics of the flagellar rod components of the Fla1 system ofR. sphaeroidesis presented in this work. We also analyze the interactions of these proteins with each other and with their neighbors, and we propose a model for the order in which they are assembled.


2017 ◽  
Vol 13 (33) ◽  
pp. 232
Author(s):  
Nafissatou Diop Ndiaye ◽  
Mady Cisse ◽  
Fatou Diop Mbacke ◽  
Abou Diop ◽  
Saliou Ndiaye ◽  
...  

Sweet corn is an underutilized crop for human consumption in Senegal. In this study, physical and biochemical characterization were performed on four sweet corn ear varieties grown at three different fertilization rate of 15N-15-P-15K. Treatment F1 was 40 tons/Ha horse-dung + 200 kg/Ha of 15N-15P-15K, treatment F2 was 30 tons/Ha horse-dung + 150 kg/Ha of 15N-15P-15K) and treatment F3 was 50 tons/Ha horse-dung + 250 kg/Ha of 15N-15P-15K. Results showed that Yosemite cultivar gave the highest number of kernels/ear (672.3), followed respectively by Legacy (642), Excellis Garrison (585.6) and Infinity (573). Furthermore, treatments using fertilizer 3 (F3: 50 tons/Ha horse-dung + 250 kg/Ha of 15N-15P-15K) led to the highest number of kernels/ear in all cultivars used. Interestingly, Legacy cultivar gave more reducing sugars (5.1 ± 0.8 g.100g -1 ) with treatment F1; treatment F3 provided less reducing sugars (2.1 ± 0.6 g.100g -1 ) and more starch (14.4 ± 0.5 g.100g -1 ). Overall, physical and biochemical characteristics were influenced to at least some extent by fertilization treatments related to the cultivar used. Yosemite and Legacy cultivars would be more suitable for canned sweet corn production in the conditions studied. Sangalkam seems to be more suitable for sweet corn production.


2000 ◽  
Vol 351 (2) ◽  
pp. 517-525 ◽  
Author(s):  
Chris TSELEPIS ◽  
Alvin P. L. KWAN ◽  
David THORNTON ◽  
John SHEEHAN

Tibial dyschondroplasia (TD) is a disorder of endochondral ossification characterized by the presence of an avascular, non-mineralized cartilage lesion extending from the growth plate into the metaphysis. Cells within the TD growth plate fail to differentiate to full hypertrophy, and instead appear to maintain a ‘pre-hypertrophic’or ‘transitional’status. Studies of the expression and distribution of cartilage matrix macromolecules in the TD growth plate have shown a marked decrease in the levels of aggrecan in the TD matrix. In the present study we compared the biochemical characteristics of the aggrecan molecules extracted from normal epiphyseal and TD cartilage. We have shown three major differences between normal and TD cartilage aggrecan. These are: (1) increase in molecular mass; (2) increase in the number of keratan sulphate chains; and (3) difference in the pattern of sulphation in TD aggrecan. Such changes in biochemical characteristics of the aggrecan monomers in TD cartilage may be associated with the lack of mineralization of the diseased cartilage. The present study provides a basis for further investigations into the importance of proteoglycans in normal and pathological bone development.


2010 ◽  
Vol 77 (5) ◽  
pp. 1881-1884 ◽  
Author(s):  
Khomaini Hasan ◽  
Andrea Fortova ◽  
Tana Koudelakova ◽  
Radka Chaloupkova ◽  
Mayuko Ishitsuka ◽  
...  

ABSTRACTWe report the biochemical characterization of a novel haloalkane dehalogenase, DatA, isolated from the plant pathogenAgrobacterium tumefaciensC58. DatA possesses a peculiar pair of halide-stabilizing residues, Asn-Tyr, which have not been reported to play this role in other known haloalkane dehalogenases. DatA has a number of other unique characteristics, including substrate-dependent and cooperative kinetics, a dimeric structure, and excellent enantioselectivity toward racemic mixtures of chiral brominated alkanes and esters.


Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.


Author(s):  
George Guthrie ◽  
David Veblen

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).


2014 ◽  
Vol 3 (3) ◽  
pp. 218-225
Author(s):  
R. G. Somkuwar ◽  
M. A. Bhange ◽  
A. K. Upadhyay ◽  
S. D. Ramteke

SauvignonBlanc wine grape was characterized for their various morphological, physiological and biochemical parameters grafted on different rootstocks. Significant differences were recorded for all the parameters studied. The studies on vegetative parameters revealed that the rootstock influences the vegetative growth thereby increasing the photosynthetic activities of a vine. The highest photosynthesis rate was recorded in 140-Ru grafted vine followed by Fercal whereas the lowest in Salt Creek rootstock grafted vines.The rootstock influenced the changes in biochemical constituents in the grafted vine thereby helping the plant to store enough food material. Significant differences were recorded for total carbohydrates, proteins, total phenols and reducing sugar. The vines grafted on1103-Pshowed highest carbohydrates and starch followed by 140-Ru,while the least amount of carbohydrates were recorded in 110-R and Salt Creek grafted vines respectively.Among the different rootstock graft combinations, Fercal showed highest amount of reducing sugar, proteins and phenols, followed by 1103-P and SO4, however, the lowest amount of reducing sugar, proteins and phenols were recorded with 110-R grafted vines.The vines grafted on different rootstocks showed changes in nutrient uptake. Considering this, the physico-biochemical characterization of grafted vine may help to identify particularrootstocks combination that could influence a desired trait in commercial wine grape varieties after grafting.


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