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This study incorporated the 43 kDa Zn-binding membrane protein isolated from common carp into liposome. The specificity and strength of the binding of 65 Zn to the 43 kDa proteinliposomes, and the binding of the 65 Zn-labeled 43 kDa protein-liposomes to laminin were studied. It was found that 65 Zn was bound to the external side of the 43 kDa protein-liposomes. Specific binding of 65 Zn to the protein-liposomes was detected. The binding parameter of Zn to the protein was found to be: maximum binding site (N max ), 76.7 pmole/µg protein (approx. 3 mole of Zn 2+ /mole); and equilibrium dissociation constant (Kd), 0.19 µM. Of the cations introduced (Ca 2+ , Cd 2+ ,Co 2+ , Cr 2+ , Cu 2+ , Fe 2+ , Hg 2+ , Mg 2+ , Mn 2+ , Ni 2+ , Pb 2+ ), only Co 2+ competed significantly with Zn. The protein-liposomes were also found to bind specifically to laminin with a N max of 1.1 pmole/µg laminin, and Kd of 4.79 µM. No significant protein-liposome binding occurred to other extracellular matrix proteins (fibronectin, fibrinogen or vitronectin). Furthermore, the binding was specifically inhibited by the Arg-Gly-Asp (RGD) peptide or GRGDSPG, while two other analogs (GRGESPG and GRADSPG) were without effect.KEY WORDS: common carp, laminin, Zn-binding protein, Zn-binding specificity and affinity, Zn.

The concentrations of Zn and sulfhydryl (SH) groups in the digestive tract tissue of common carp and some aquatic animals were studied. It was found that Zn and bound SH groups could be used as indicators for detecting the Zn‐binding protein in the digestive tract tissue of common carp. The digestive tract tissue of the fish underwent subcellular fractionation, and it was found that the nuclei/cell debris fraction contained most of the DNA (85%), Na+/K+‐ATPase (82%), organic phosphate (90%) and the Zn‐binding protein (79%), but only part of the 5′‐nucletidase and alkaline phosphatase (<23%). The nuclei/cell debris fraction of the digestive tract tissue of common carp was treated with either collagenase type I or type IV, and subfractionated by sucrose density centrifugation. It was found that treatment with collagenase type IV could release more than 50% of the Zn‐binding protein, Na+/K+‐ATPase and organic phosphate from collagen. Sections of digestive tract tissue of common carp were stained for Zn. It was observed that Zn can be found mainly on the edge of the epithelial layer, and everywhere in the ‘membrane‐like’ portion of the submucosal and muscular layers. It is proposed that most of the Zn‐binding protein in the digestive tract tissue of common carp is located on the basolateral plasma membranes of the epithelial cells and on the surrounding muscle cells that are attached to the collagen type IV of basal laminae.

C57BL/6J mice were divided into control group (C), CLA, c9t11, or t10c12 groups. CLA and t10c12 significantly increased α-tocopherol levels in the plasma and various tissues in experiment 1. The CLA and t10c12 groups also showed a significant increase in hepatic α-tocopherol transfer protein (α-TTP) levels. In experiment 2, mice were divided into control, CLA, R (rosiglitazone, a PPARγ agonist), or CLA+R groups. Vitamin E levels in the liver, epididymal fat pad, kidney, and plasma were increased by CLA, and this effect was reduced in the CLA+R group. t10,c12-CLA is the most active isomer in the CLA mixture in the regulation of tissue vitamin E status and α-TTP protein levels in mice. The increase in liver vitamin E status in CLA-fed mice is mainly due to the effect of PPARγ inhibition.

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