Amino acid composition, VIII

Hence, we have made comparisons of amino acid compositions of a-lactalbumins (Table VI), mammalian c-type lysozymes (Table VII), and egg-white lysozymes (a variety of c type and one g type) (Table VIII). Where the sequence information is available, the compositions have been deduced from these results otherwise, the amino acid compositions are obtained from amino acid analysis of the protein. 

We now examine how the FeS-X cluster is coordinated to the protein and the relationship ofthe FeS-X domain with the surrounding protein environment. In the PS-I heterodimer there are five cysteine residues, three conserved cysteines in the PsaA and two conserved cysteines in the PsaB subunit. Ofthe five, two from each subunit are implicated as ligands for binding the [4Fe 4S] cluster of FeS-X. In Fig. 11 there are two cysteine residues present in the loops between helices VIII and IX of the PsaA and PsaB subunits of Synchococcus sp. PCC 7002. In fact, as seen from the amino-acid composition of the two loops in Fig. 11 (B), a conserved sequence with a CDGPGRGGTC motif is present in both PsaA and PsaB. It was readily envisioned that, in the PS-I reaction-center core, Cys-582 and Cys-591 in PsaA and Cys-560 and Cys-569 in PsaB [see Fig. 11 (B)], might serve as ligands for the coordination of the [4Fe 4S] cluster of FeS-X. 

Fig. 11. (A) Model for the homologous PsaA (and PsaB) subunits of photosystem I. Helices VIII and IX and the VIII-IX interhelical loop are shown inside the dashed ellipse (B) Amino-acid composition of the loop between helices VIII and IX in PsaA and PsaB. with the four cysteine residues numbered for Synechococcus sp. PCC 7002 and Synechocystis sp. PCC 6803, respectively (separated by a slash). (C) A working model for the FeS-X domain consisting of a bundle of four a-helices (VIII and IX from PsaA and PsaB), the interhelical loops and FeS-X itself ligated to the four cysteine residues. Model in (C) is adapted from Rodday, Jun and Biggins (1993) Interaction of the Ff Fg-containing subunit with the photosystem I core heterodimer. Photosynthesis Res 36 3.

The preparation and the assay of the components of fibrinolysis and thrombolysis have been reviewed." The amino-acid sequences at the NH2-terminus, molecular weights, and amino-acid compositions of human prothrombin, factors IX and X, and a new plasma protein have been compared." Desialylation of human plasma factor VIII decreased its ristocetin-induced platelet-aggregation activity and facilitated its clearance by hepatocytes, but its procoagulant activity was not affected." " Experiments in vivo have confirmed the view that the inhibi-... 

The amino acid composition of homogeneous components of some protamines is described in Chaps. VII and VIII. 

TNP-YI, TNP-Z and free YII were indeed successfully separated by one-step elution of modified whole clupeine from a CM-cellulose column as shown in Fig. VII-7 [Ando and Suzuki, 1966 Suzuki and Ando, 1968 (2)]. The amino-acid composition of TNP-clupeine Z agrees with that estimated for homogeneous clupeine Z (Ando et al. 1962 Azegami et aL 1970). TNP-alanine is known to yield free alanine during acid hydrolysis (Okuyama and Satake, 1960). The molar ratios of the amino-acid content of free clupeine YII and TNP-clupeine YI proved to be simple integral numbers in the structural studies (see Chap. VIII. B and C), in which accurate analysis of the amino-acid composition and the N-terminus confirmed their homogeneity. 

The behaviour of each fraction on disc electrophoresis in 8 M urea at pH 4.5 was as follows. Fractions G-I—G-III gave 2 bands each, G-IV—G-VI1 band each, G-VII1 main and 2 minor bands, and G-VIII 1 main and 3 minor bands. The amino-acid composition, and... 

Table VIII-1. Amino-acid composition of clupeine Z (Amino-acid N as a percentage of...

Peaks obtained by column chromatographic separation (Fig. VIII-1) of tiyptic peptides in a 20-h digest of clupeine Z were analyzed for their amino-acid composition, amino termini, etc. to determine the structure and amounts of peptides involved... 

Pressor hormone, of posterior pituitary, activity, VII, 385, 390 circulatory, VII, 390, 405 hyperglycemic, VIII, 233, 234 oxytocic, VIII, 228 amino acids in, VII, 383 composition, VII, 385 diabetes insipidus and, VIII, 245 effect on alimentary tract, VIII, 218-225... 

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