scholarly journals A study of the properties of two porphyringlobin species formed in the reaction of protoporphyrin IX with human globin

1974 ◽  
Vol 137 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Stanley Ainsworth ◽  
Amyra Treffry

Globin was prepared from the main (A0) component of human haemoglobin and reacted with protoporphyrin IX; the product, when subjected to chromatography on CM-Sephadex, separated into fast- and slow-moving species. These were isolated for examination. The dissociation constant for the tetramer–dimer equilibrium of fast-moving porphyringlobin was determined at 2.8X10−6m; this is to be compared with values of 2.2X10−6m and 8X10−8m determined for oxyhaemoglobin and the slow-moving porphyringlobin respectively. It was also shown that the thiol groups of fast-moving porphyringlobin react with 4,4′dithiodipyridine at an identical rate with those of oxyhaemoglobin; in comparison, the rates of reaction of deoxyhaemoglobin and porphyringlobin are much slower but are again identical with one another. The quenching of porphyringlobin fluorescence by I− ions was also studied. The quenching could not be represented by a simple Stern–Volmer relationship (whereas that of porphyrin–apomyoglobin is), but was represented by a model in which the fluorescence of fast-moving porphyringlobin was more accessible to the quencher than that of the slow-moving component. Similarly, fast-moving porphyringlobin was photodecomposed more rapidly by oxygen than the slow-moving species.

1974 ◽  
Vol 137 (2) ◽  
pp. 339-348 ◽  
Author(s):  
Amyra Treffry ◽  
Stanley Ainsworth

The fluorescence of porphyringlobin is quenched on adding haemoglobin to its solutions. It is suggested that this result indicates the formation of hybrids (comprising a dimer of porphyringlobin and a dimer of haemoglobin) in which quenching occurs by energy transfer from the porphyrin to the haem groups of the protein. From an analysis of fluorescence quenching, dissociation constants were calculated for the hybrids of oxy- and deoxyhaemoglobin with the fast- and slow-moving porphyringlobin species isolated by chromatography on CM-Sephadex (Treffry & Ainsworth, 1974). The values obtained are: deoxyhaemoglobin–fast-moving porphyringlobin, 0.8X10−9m; deoxyhaemoglobin–slow-moving porphyringlobin, 5X10−10m; oxyhaemoglobin–fast-moving porphyringlobin, 0.8X10−6m; oxyhaemoglobin–slow-moving porphyringlobin, 1.2X10−7m. The rates of reactions of solutions of haemoglobin and porphyringlobin, containing hybrids, with the thiol reagent 4,4′-dithiodipyridine showed that the thiol groups of the hybrids deoxyhaemoglobin–fast-moving porphyringlobin and oxyhaemoglobin–slow-moving porphyringlobin react more slowly than expected on the basis of composition alone: this result indicates that the deoxy and slow-moving conformations are the more stable, imposing themselves partially on to the fast-moving or oxy dimer of the hybrid. Also the rate of the reaction of CO with deoxyhaemoglobin is decreased when slow-moving porphyringlobin is added to its solutions: this is reflected in a movement of the oxygen equilibrium curve of such a mixture to higher oxygen partial pressures. Similar experiments with deoxyhaemoglobin solutions containing fast-moving porphyringlobin, showed an initial increase in the rate of CO uptake. Correspondingly, the oxygen equilibrium curve of the mixture showed an increased affinity for oxygen. Approximate calculations to determine the oxygen equilibria of the hybrids indicate that a functional dimer retains co-operative characteristics even when the dimer accompanying it within the tetramer has the reacted conformation.


Humaniora ◽  
2011 ◽  
Vol 2 (2) ◽  
pp. 1309
Author(s):  
Handy Martinus

Fast moving in retail industry is the latest trading industry in trading chain. The study is to identify the condition of retail industry in Indonesia. This uses normative juridical approach. The research material is gathered by literature or document review. The analysis for modern retail industry is conducted through qualitative, thus explaining law material gathered from library being selected, arranging systematically, and finally getting conclusion figured to answer problems related to the rules for monopoly and dysfunction business competition in retail industry. The study result showed that modern market, which so far having a good performance, will have challenges. One biggest challenge is the potential for slow-moving revenue growth as the effects of slow-moving economic caused by global crisis.  


2021 ◽  
Vol 15 (1) ◽  
pp. 60
Author(s):  
Amri Yanuar ◽  
Marwanto Rahmatuloh ◽  
Ilman Mutaqien

Operasional gudang memiliki berbagai aktivitas inti yang saling berkaitan satu dengan yang lainnya, seperti aktivitas receiving, storage, dan picking. Aktivitas inti ini atau yang biasa disebut inbound dan outbound harus dikerjakan dalam waktu yang singkat dan meminimalisir tingkat kesalahan agar tidak mengganggu keberlangsungan alur masuk dan keluarnya barang di gudang. Beberapa hal yang dapat mengganggu aliran barang di gudang di antaranya adalah terjadinya bottle neck di area receiving, waktu proses pencarian barang yang lama, dan 70% waktu proses order picking di bawah waktu standar. Permasalahan-permasalahan ini terjadi salah satunya dikarenakan pengelolaan barang di gudang masih manual atau belum menggunakan sistem informasi. Tujuan dari penelitian ini adalah merancang sistem informasi untuk membantu operasional gudang guna meminimalisir kesalahan-kesalahan yang dapat mengganggu aliran masuka dan keluarnya barang dari gudang, dengan menggunakan pendekatan FSN Analysis. Hasil dari pengolahan data menggunakan FSN Analysis ini, dapat membantu dalam mengetahui produk-produk yang masuk kedalam kategori fast moving, slow moving, dan non-moving.


1978 ◽  
Vol 3 (4) ◽  
pp. 249-250 ◽  
Author(s):  
K. V. Sheridan ◽  
B. V. Jackson ◽  
D. J. McLean ◽  
G. A. Dulk

Studies of coronal transients observed in white-light (Gosling et al., 1976) have shown that fast-moving events (≤ 400 km s-1) are closely associated with flares and with type II and IV radio bursts while slow-moving events are not. We now report the first detection of the radio counterpart of a slow-moving transient. The event of 1974 January 21 is shown to be visible on maps of the quiet Sun made at a frequency of 80 MHz.


1977 ◽  
Vol 165 (1) ◽  
pp. 141-148 ◽  
Author(s):  
C C Winterbourn ◽  
R W Carrell

Addition of Cu(II) ions to human oxyhaemoglobin caused the rapid oxidation of the haem groups of the beta-chain. Oxidation required binding of Cu(II) to sites involving the thiol group of beta-93 residues and was prevented when these groups were blocked with iodoacetamide or N-ethylmaleimide. Equilibrium-dialysis studies showed three pairs of binding sites, two pairs with high affinity for Cu(II) and one pair with lower affinity. It was the second pair of high-affinity sites that were blocked with iodoacetamide and were involved in haem oxidation. Cu(II) oxidized deoxyhaemoglobin at least ten times as fast as oxyhaemoglobin, and analysis of rates suggested that binding rather than electron transfer was the rate-determining step. No thiol-group oxidation to disulphides occurred during the period of haem oxidation, although it did occur subsequently in the presence of oxygen, or when Cu(II) was added to methaemoglobin. It is proposed that thiol oxidation did not occur because there exists a pathway of electron transfer between the haem group and copper bound to the beta-93 thiol groups. The route for this electron transfer is discussed, as well as the implications as to the function of the beta-93 cysteine in the haemoglobin molecule.


1994 ◽  
Vol 20 ◽  
pp. 183-186 ◽  
Author(s):  
S. Anandakrishnan ◽  
R. B. Alley

Microearthquakes at the base of slow-moving Ice Stream C occur many times more frequently than at the base of fast-moving Ice Stream B. We suggest that the microearthquake source sites are so-called “sticky spots”, defined as limited zones of stronger Subglacial material interspersed within a weaker matrix. The fault-plane area of the microearthquakes (O(102m2)) is therefore a measure of the size of the sticky spots. The spatial density of the microearthquakes (O(10 km-2)) is a measure of the distribution of sticky spots.The average stress drop associated with these microearthquakes is consistent with an ice-stream bed model of weak subglacial till interspersed with stronger zones that support much or all of the basal shear stress. We infer a weak inter-sticky-spot material by the large distances (O(103m)), relative to fault radius, to which the microearthquake stress change is transmitted.


Author(s):  
Clyde A. Leys

ABSTRACTThe Recent Saefell tuff-ring on Heimaey, Iceland was formed by surtseyan activity in shallow seawater. The tuff-ring has a basal diameter of about 3 km, a maximum rim height of 188 m above sea-level and a crater diameter of 1300 m. Three tuff-units are recognised, separated by unconformities on and inside the crater rim due to syndepositional slumping. The crater contains a nested rim which was constructed above slumped crater tuffs. Directional data indicate strongly directed blasts to the SW at a late stage in the activity.Throughout the volcanic activity, base-surges formed antidunes, U-shaped channels, vesiculated tuffs, small ripples and plastering structures. One antidune reflects a decrease in surge flow power during deposition and subsequent slumping due to base-surge drag and instabilities developed during growth. On the basis of field characteristics, the structures are divided into those deposited by hot, dry, fast-moving surges and those by cooler, wet, slow-moving surges. Base-surges are compared with turbidity currents and deposition of distinct structures by the head, body and tail regions is interpreted.


1987 ◽  
Vol 65 (11) ◽  
pp. 2682-2689 ◽  
Author(s):  
E. Nol ◽  
D. E. Gaskin

Distribution and movement patterns are described for summering (nonbreeding) Black Guillemots in the Deer Island region of the southwestern Bay of Fundy, Canada. Guillemots were distributed in areas with moderate current velocities (range, 30–68 cm/s) and shallow to intermediate depths (range, 17–31 m). The birds appeared to avoid shallow and deep areas with fast- or slow-moving water. Guillemots preferred islands with extensive underwater ledges, presumably because these harboured sufficient prey and provided protection from fast-moving tidal waters. Guillemots moved in and out of the approaches passively with the tide and, in contrast to larids in the region, made only small-scale flights to reposition themselves in relation to food resources.


2014 ◽  
Vol 97 ◽  
pp. 113-123 ◽  
Author(s):  
Emmanuelle Pouydebat ◽  
Antony Borel ◽  
Hélène Chotard ◽  
Dorothy Fragaszy

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