Internal ligation

Battezzati, Mario, Alberto Tagliaferro and Angelo Domenko Cattaneo, Clinical Evaluation of Bilateral Internal Mammary Artery Ligation as Treatment of Coronary Heart Disease , American Journal of Cardiology 4 (1959) 180-83... 

Machova Z, Muhle C, Krauss U, Trehin R, Koch A, Merkle HP, Beck-Sickinger AG (2002) Cellular internalization of enhanced green fluorescent protein ligated to a human calcitonin-based carrier peptide. Chem Biochem 3 672-677. 

Figure 2.4. In vivo measurement of blood-brain barrier (BBB) permeability, (a) Internal carotid artery perfusion technique (i) in the rat. Other branches of the carotid artery are ligated or electrically coagulated (o, occipital artery p, pterygopalatine artery). The external carotid artery (e) is cannulated and the common carotid artery (c) ligated. Perfusion time may range from 15 s to 10 min, depending on the test substance. It is necessary to subtract the intravascular volume, Vo, from (apparent volume of distribution), to obtain true uptake values and this may be achieved by inclusion of a vascular marker in the perfusate, for example labelled albumin. Time-dependent analysis of results in estimates of the unidirectional brain influx constant Ki (pi min which is equivalent within certain constraints to the PS product. BBB permeability surface area product PS can be calculated from the increase in the apparent volume of distribution Vd over time. Capillary depletion, i.e. separation of the vascular elements from the homogenate by density centrifugation, can discriminate capillary uptake from transcytosis. (b) i.v. bolus kinetics. The PS product is calculated from the brain concentration at the sampling time, T, and the area under the plasma concentration-time curve, AUC.

The structure of PaFd was the first to be crystallographically determined (Adman et ai, 1973). The basic fold of the protein may be described as a pair of two stranded antiparallel )3 sheets. The two 4Fe 4S clusters are sandwiched between these /3 strands on one side and several helical segments on the other side. The clusters are packed in a predominantly hydrophobic environment. The internal sequence homology is clearly reflected in the structure the two clusters and much of the polypeptide chain are related by an approximate internal twofold rotation axis. The two clusters are ligated by the two sets of four cysteines in the two halves of the molecule. Surprisingly, each cluster is liganded by cysteines from both halves of the sequence, rather than cysteines from only one half (which are adjacent in the sequence). Cluster 1 is coordinated by Cys-8, -11, and -14 in the amino-terminal half and Cys-45 of the carboxy-terminal half, while cluster 2 is coordinated by Cys-35, -38, and -41 of the carboxy-terminal half and Cys-18 of the amino-terminal half. 

Cobb LA, Thomas GI, Dillard DH, Merendino KA, Bmce RA. An evalnation of internal-mammary-artery ligation by a donble-bhnd techniqne. N Engl J Med 1959 260 1115-8. 

Sun, L., Ghosh, I., Xu, M.Q. (2003). Generation of an affinity column for antibody purification by intern-mediated protein ligation. J. Immunol. Methods, 282(1-2), 45-52. 

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