Conformational and functional significance of residue proline 17 in chicken muscle adenylate kinase

AbstractThe effect of mutation proline 17 on the multiple conformations and catalytic function in chicken muscle adenylate kinase (AK) has been studied. The substitution of proline 17 with glycine or valine altered the distribution of multiple conformations. Compared with the wild-type enzyme, the P17G and P17V mutants contained decreased fraction of minor conformer from 18% to 9% and 11%, respectively. Due to the mutation, the enzyme showed lower secondary structural content, poorer affinity to substrates or substrate analogues, and reduced catalytic efficiency. The results revealed the significance of proline 17 in the conformation and function of AK

Effects of Migration and Diffusion of Suspended Sediments on the Seabed Environment during Exploitation of Deep-Sea Polymetallic Nodules

With the increase in demand for metal resources, research on deep-sea polymetallic nodule mining has been reinvigorated, but the problem of its environmental impact cannot be ignored. No matter what method is used for mining, it will disturb the surface sediments of the seabed, thereby increasing the concentration of suspended solid particles and metal ions in the water body, changing the properties of the near-bottom water body and sediments, and affecting biological activity and the living environment. Focusing on the ecological and environmental impacts of deep-sea polymetallic nodule mining, taking as our main subject of focus the dynamic changes in sediments, we investigated the environmental impacts of nodule mining and their relationships with each other. On this basis, certain understandings are summarized relating to the ecological and environmental impacts of deep-sea polymetallic nodule mining, based on changes in the engineering geological properties of sediment, and solutions for current research problems are proposed

Effects of Migration and Diffusion of Suspended Sediments on the Seabed Environment during Exploitation of Deep-Sea Polymetallic Nodules

With the increase in demand for metal resources, research on deep-sea polymetallic nodule mining has been reinvigorated, but the problem of its environmental impact cannot be ignored. No matter what method is used for mining, it will disturb the surface sediments of the seabed, thereby increasing the concentration of suspended solid particles and metal ions in the water body, changing the properties of the near-bottom water body and sediments, and affecting biological activity and the living environment. Focusing on the ecological and environmental impacts of deep-sea polymetallic nodule mining, taking as our main subject of focus the dynamic changes in sediments, we investigated the environmental impacts of nodule mining and their relationships with each other. On this basis, certain understandings are summarized relating to the ecological and environmental impacts of deep-sea polymetallic nodule mining, based on changes in the engineering geological properties of sediment, and solutions for current research problems are proposed

ROTATIONALLY RESOLVED LIF SPECTRUM OF A~2A1←X~2E\tilde{A} ^{2}A_{1} \leftarrow \tilde{X} ^{2}E TRANSITION OF CH3SCH_{3}S AND THE A~2A1\tilde{A} ^{2}A_{1} STATE SPIN-ROTATION CONSTANT OF CHOCH_{O}

$^{1}$ Y. Endo, S. Saito, and E. Hirota. J. Chem. Phys. 85. 1770 (1986).Author Institution: Laser Spectroscopy Facility. Department of Chemistry, The Ohio State University; Institute of Atomic \& Molecular Science, Academia Sinica.; Department of Chemistry, Florida State UniversityThe rotationally resolved laser - induced fluorescence spectrum $\tilde{A} ^{2}A_{1} \rightarrow \tilde{X} ^{2}E$ of the methylthio radical has been obtained in a free-jet supersonic expansion. A detailed rotational analysis of the electronic transition has been carried out. A joint least square fitting of the present electronic transitions and previously observed microwave $transitions^{1}$ yields ground and excited state molecular constants. The ground state constants are considerably revised from those previously reported, while the excited state values have been accurately determined for the first time in this experiment. Particularly interesting are the very large values of the ground state spinrotation constants in $CH_{3}S$ and $CH_{3}O.$ To develop more understanding of the spinrotation interaction in these radicals, a high resolution LIF spectrum of $\tilde{A} ^{2}A_{1} \rightarrow \tilde{X} ^{2}E$ transition of $CH_{3}O$ has been taken and the upper state spin-rotation constants have been determined

Wheat-Bran-Based Artificial Diet for Mass Culturing of the Fall Armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae)

Spodoptera frugiperda Smith (fall armyworm (FAW)) has invaded many countries in Africa and Asia in recent years, considerably restricting global agricultural production. In this study, we assessed the rearing performance of four artificial diets (D1: an artificial FAW diet based on wheat bran and soybean, maize, and yeast powders; D2: an artificial diet developed for Helicoverpa armigera (Hübner), based on wheat bran and soybean and yeast powders; D3: an artificial diet based on soybean powder; D4: an artificial diet based on wheat bran) for FAWs. We designed D4 based on a traditional diet (D2) but substituted the wheat bran for soybean and yeast powders. At 25 ± 1 °C, 75% ± 5% RH, and a 16:8 h L:D photoperiod, the larval stage of FAWs fed on D4 lasted 15.88 d, the pupal stage lasted 9.48 d, the pupal mass was 270.45 mg, the number of eggs deposited was 1364.78, and the mating rate was 89.53%. Most biological indicators of the larvae that were fed D4 were basically consistent with those of the larvae fed on the traditional diet (D2), but the intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0) of the D4 FAWs were lower than those of the D2 FAWs. The flight capacity (flight distance, duration, and velocity were 19.73 km, 6.91 h, and 2.90 km/h, respectively) of the D4 FAWs was comparable to that of the FAWs fed a traditional diet and maize leaves. Compared with the three other formulas, the cost of using D4 was lower by 26.42% on average. These results show that using cheap wheat bran instead of soybean flour and yeast powder as the basic material for an artificial diet for FAWs is feasible, which will substantially reduce rearing costs and promote the development of new controlling measures for FAWs. In addition, this study also has a reference value for reducing the cost of artificial diets for other insects