Minimalistic Predictor of Protein Binding Energy: Contribution of Solvation Factor to Protein Binding

Small clusters of water (H2O)n, n = 3-8, are studied using a semiempirical valence bond approach to investigate the bonding energy contribution and hydrogen-bonding structure in the most stable conformation. The energy contribution was decomposed into electron pair-pair interactions and valence-bond energy for each water monomer. Our study shows that there is significant bonding difference between small clusters (n [Formula: see text] 5) of water and larger clusters (n > 5). In the larger clusters, there are structures containing tetravalent oxygen centers, which is impossible in the small clusters. The contribution to the binding energy from each H-bond varies from -4.7 kcal/mol to -7.3 kcal/mol in the water clusters considered here. The contribution of -5.9 kcal/mol per H-bond in the cubic octamer is comparable to the experimental value (-6.7 kcal/mol) of the binding energy in ice.Keywords: semi-empirical, valence bond, hydrogen bonding, water clusters.

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Transient Prealbumin- Associated Hyperthyroxinemia in TSH-Producing Pituitary Adenoma

Nuklearmedizin ◽

10.1055/s-0038-1629511 ◽

1990 ◽

Vol 29 (01) ◽

pp. 40-43 ◽

Cited By ~ 3

Author(s):

W. Langsteger ◽

P. Költringer ◽

P. Wakonig ◽

B. Eber ◽

M. Mokry ◽

...

Keyword(s):

Computed Tomography ◽

Case Report ◽

Pituitary Adenoma ◽

Thyroid Hormones ◽

Protein Binding ◽

Alpha Subunit ◽

Normal Range ◽

Thyroxine Binding Globulin ◽

Free Thyroid Hormones ◽

Transmission Computed Tomography

This case report describes a 38-year-old male who was hospitalized for further clarification of clinically mild hyperthyroidism. His increased total hormone levels, the elevated free thyroid hormones and the elevated basal TSH with blunted response to TRH strongly suggested a pituitary adenoma with inappropriate TSH incretion. Transmission computed tomography showed an intrasellar expansion, 16 mm in diameter. The neoplastic TSH production was confirmed by an elevated alpha-subunit and a raised molar alpha-sub/ATSH ratio. However, T4 distribution on prealbumin (PA, TTR), albumin (A) and thyroxine binding globulin (TBG) showed a clearly increased binding to PA (39%), indicating additional prealbumin-associated hyperthyroxinemia. The absolute values of PA, A and TBG were within the normal range. After removal of the TSH-producing adenoma, basal TSH, the free thyroid hormones and T4 binding to prealbumin returned to normal. Therefore, the prealbumin-associated hyperthyroxinemia had to be interpreted as a transitory phenomenon related to secondary hyperthyroidism (T4 shift from thyroxine binding globulin to prealbumin) rather than a genetically conditioned anomaly of protein binding.

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Absorption, Metabolic Stability and Protein Binding Properties of Sutherlandioside B from Sutherlandia frutescens

Planta Medica ◽

10.1055/s-2008-1075256 ◽

2008 ◽

Vol 74 (03) ◽

Author(s):

VLM Madgula ◽

B Avula ◽

X Fu ◽

XC Li ◽

TJ Smillie ◽

...

Keyword(s):

Protein Binding ◽

Metabolic Stability ◽

Binding Properties ◽

Sutherlandia Frutescens

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Controlled modulation of the binding energy of impurity states in a quantum-well system

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.0166.199604i.0447 ◽

1996 ◽

Vol 166 (4) ◽

pp. 447-448 ◽

Cited By ~ 1

Author(s):

Vladimir I. Belyavskii ◽

Yurii V. Kopaev ◽

N.V. Kornyakov

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Impurity States

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INCORPORATION OF IODIDE INTO ORGANIC COMPOUNDS IN THE GUINEA PIG THYROID

Acta Endocrinologica ◽

10.1530/acta.0.0430110 ◽

1963 ◽

Vol 43 (1) ◽

pp. 110-118 ◽

Cited By ~ 2

Author(s):

R. Ekholm ◽

T. Zelander ◽

P.-S. Agrell

Keyword(s):

Guinea Pig ◽

Protein Binding ◽

Organic Compounds ◽

Guinea Pigs ◽

Microsomal Fraction ◽

Thyroid Tissue ◽

Particulate Fraction ◽

Supernatant Fraction ◽

Hydrolysis Of

ABSTRACT Guinea pigs, kept on a iodine-sufficient diet, were injected with Na131I and the thyroids excised from 45 seconds to 5 days later. The thyroid tissue was homogenized and separated into a combined nuclear-mitochondrial-microsomal fraction and a supernatant fraction by centrifugation at 140 000 g for one hour. Protein bound 131iodine (PB131I) and free 131iodide were determined in the fractions and the PB131I was analysed for monoiodotyrosine (MIT), diiodotyrosine (DIT) and thyroxine after hydrolysis of PB131I. As early as only 20 minutes after the Na131I-injection almost 100% of the particulate fraction 131I was protein bound. In the supernatant fraction the protein binding was somewhat less rapid and PB131I values above 90% of total supernatant 131I were not found until 3 hours after the injection. In all experiments the total amount of PB131I was higher in the supernatant than in the corresponding particulate fraction. The ratio between supernatant PB131I and pellet PB131I was lower in experiments up to 3 minutes and from 2 to 5 days than in experiments of 6 minutes to 20 hours. Hydrolysis of PB131I yielded, even in the shortest experiments, both MIT and DIT. The DIT/MIT ratio was lower in the experiments up to 2 hours than in those of 3 hours and over.

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