Structure and function of cell binding domain of fish extracellular matrix components

1.比较了日本鲶鱼肝细胞（JCHC）与日本鲶鱼血浆纤维连接蛋白（JCpFN-I）结合，与未与牛pFN（BpFN）结合的日本鲶鱼肝细胞（JCHC）和与两种pFN结合的鳗鱼肝细胞（EHC）与JCpFN-I、JCpFN-I和BpFN的治疗片段、BpFN的亚丁基蛋白酶和胃蛋白酶消化片段的结合能力。从这些结果中得出的结论如下。(1)JCpFN-1和BpFN似乎具有各自的双细胞结合结构域，其中一个是带有整合素识别序列“RGD”的EHC结合结构域，另一个是不带RGD序列的JCHC结合结构域。(2)两个以上的结构域似乎是必要的JCHC和TCpFN-I之间的成功结合。(3)JCHC与BpFN结合能力的缺陷可能是由于BpFN中的JCHC结合结构域被结合抑制结构域所掩盖.比较了罗非鱼肝细胞（THC）与罗非鱼血浆纤维连接蛋白（TpFN-I）结合、与鲤鱼pFN（CpFN-I）不结合的THC和与两种pFN结合的鳗鱼肝细胞（EHC）与TpFN-I、TpFN-I和CpFN-I的治疗性片段以及CpFN-I的链霉蛋白酶消化片段的结合能力。从这些结果中得出的结论如下。(1)TpFN-Ⅰ和CpFN-Ⅰ具有独立的两个细胞结合结构域，一个是含RGD序列的EHC结合结构域，另一个是含RGD序列的THC结合结构域。(2)THC与CpFN-I结合能力的缺陷可能是由于CpFN-I的THC结合结构域被结合抑制结构域所掩盖.从鲤鱼皮I型胶原蛋白CB肽中分离到分子量为25 kDa的细胞结合区。细胞结合域与鲤鱼鳍成纤维细胞和鲤鱼肝细胞具有结合能力，且具有RGD依赖性。氨基端（24个残基）由8个Gly-X-Y重复序列和2个Pro残基组成。表明细胞结合结构域具有松散的构象。

1. Japanese catfish hepatocyte (JCHC) which combined with Japanese catfish plasma fibronectin (JCpFN-I) and did not with bovine pFN (BpFN) was compared with eel hepatocyte (EHC) which combined with both pFNs in binding abilities to JCpFN-I, thermolytic fragments of JCpFN-I and BpFN, and subutilisin and pepsin-digested fragments of BpFN. The conclusions to be drawn from these results were as follows. (1) JCpFN-I and BpFN seemed to have individual two cell binding domain, one of them was EHC binding domain with integrin recognition sequence "RGD" and another was JCHC binding domain without RGD sequence. (2) More than two domains seemed to be necessary for successful binding between JCHC and TCpFN-I. (3) Defective binding ability of JCHC to BpFN seemed possible to be caused by the masking of JCHC binding domain in BpFN with a binding inhibition domain.2. Tilapia hepatocyte (THC) which combined with Tilapia plasma fibronectin (TpFN-I) and did not with carp pFN (CpFN-I) was compared with eel hepatocyte (EHC) which combined with both pFNs in binding abilities to TpFN-I, thermolytic fragments of TpFN-I and CpFN-I, and pronase-digested fragments of CpFN-I. The conclusions to be drawn from these results were as follows. (1) TpFN-I and CpFN-I seemed to have individual two cell binding domain, one of them was EHC binding domain with RGD sequence and another was THC binding domain with RGD sequence. (2) Defective binding ability of THC to CpFN-I seemed possible to be caused by the masking of THC binding domain in CpFN-I with a binding inhibition domain.3. The cell binding domain with 25 kDa was separated from CB-peptide of carp skin type I collagen. The cell binding domain had a binding ability to carp fin fibroblast with RGD-dependent manner and carp hepatocyte. The amino terminal region (24 residues) consisted of 8 repeats of Gly-X-Y and two residues of Pro. Suggesting that the cell binding domain had loose conformation.