Age-related Changes in Bovine α-crystallin and High-molecular-weight Protein

The high-molecular-weight (HMW) protein from the lens is composed mostly of α-crystallin in a highly aggregated state. Bovine HMW protein was carefully separated from α-crystallin by size-exclusion chromatography. α-Crystallin has chaperone-like ability whereby it stabilizes other proteins under conditions of stress (e.g. heat). Comparison of bovine HMW protein and α-crystallin shows that the HMW protein has a markedly reduced chaperone ability compared to α-crystallin. However, in contrast to the results of other workers, we observe no alteration with age in the ability of α-crystallin to act as a chaperone. Using electrospray ionisation mass spectrometry, changes in the phosphorylation of the α-crystallin subunits with age have been quantified. Phosphorylation of α-crystallin occurs early in life but does not alter in proportion after about three years of age. In addition, phosphorylation of the A subunit of α-crystallin has little effect on its chaperone ability. As is found in the artificially prepared HMW complex of α- and γ-crystallin, NMR spectroscopy shows that in the naturally occurring HMW protein, the short C-terminal extension of the α_Bsubunit has lost its flexibility whereas the α_Asubunit extension is still flexible. Post-translational modifications therefore seem to have little effect on the chaperone action of α-crystallin, but alterations in the quaternary structure of α-crystallin via incorporation into the HMW aggregate, lead to major changes in the chaperone ability of the protein. The results are consistent with the notion that one of the contributing factors to cataract formation in the lens is the depletion of α-crystallin with age as it is converted into the HMW protein.     

唾液蛋白与脾肾两虚、气血不足的关系

实验表明,脾肾两虚、气血不足患者唾液蛋白明显下降,与正常人相比差异明显(P<0.01);脾肾两虚患者唾液蛋白与血浆白蛋白及总蛋白量成正相关性,气血不足患者唾液蛋白与血色素、红细胞量亦成正相关性。     

从包涵体中纯化重组人幽门螺杆菌热休克蛋白A亚单位

目的：建立一种有效从包涵体中纯化重组人幽门螺杆菌热休克蛋白A亚单位HspA的方法。方法：重组基因工程大肠杆菌发酵后，表达的Hp r HspA包涵体经洗涤，变性，复性，采用Q Sepharose High Performance阴离子交换层析和Superdex75凝胶过滤层析分离纯化，使用SDS－PAGE和HPLC检测纯度，选用ELISA和动物实验对纯化蛋白的免疫学活性和生物学活性进行鉴定。结果：Hp的HspA包涵经洗涤和溶解后，Hp的HspA的纯度＞60％，包涵体溶解液经阴离子交换层析和凝胶过滤层析后纯度超过95％，Hp的HspA纯品经检测具有良好的免疫学活性和生物学活性。结论：本研究建立的分离纯化方法可从包涵体中获得高纯度的重组HspA蛋白，为进一步的动物实验研究奠定了基础。     

IN VITRO ANALYSIS OF τ PHOSPHORYLATION SITES AND ITS BIOLOGICAL ACTIVITY

INTRODUCTIONThemicrotubule－associatedprotein蚲ishyperphos－phorylatedandglycosylatedinAlzheimerdisease（AD），andtheseabnormalmodificationsformedthebasisofprogressivelyretrogradeneurofibrillarydegenerationseeninADbrainandtherebythedementia（１，２）．ADab－normallyphosphorylated蚲notonlyismicrotubuleas－semblyincompetent，butalsoinhibitsassemblyanddis－assemblesthepreassembledmicrotubulesinvitro（３）．Inthetangle－bearingneuronsinADbrain，thenormalcytoskeletonisdisruptedandreplacedwi…     

Ubiquitin and heat shock protein expression in amyotrophic lateral sclerosis

The expression of two heat shock proteins, HSP72 and p57, in addition to ubiquitin, has been studied immunocytochemically in nine amyotrophic lateral sclerosis (ALS) cases and 10 age-matched controls. HSP72 and p57 antibodies did not identify the characteristic ubiquitin-immunoreactive inclusions present in anterior horn cells in ALS spinal cord. Antibodies to HSP72, but not to p57 or ubiquitin, strongly labelled structures corresponding to polyglucosan bodies in spinal grey matter. Such immunoreactive profiles were more abundant in ALS cases, although they were also present in control material. They were sometimes identified by haematoxylin and eosin and periodic acid Schiff reaction, but were not labeled by phosphotungstic acid haematoxylin or by antibodies to glial fibrillary acidic protein. Although ubiquitin, HSP72 and p57 are stress-induced proteins, they are expressed differently and might therefore have different significance in neuronal degeneration.     

肥胖患者血清C-反应蛋白水平变化与代谢综合征的关系

目的　比较肥胖患者急性期标志 -血清C 反应蛋白 (CRP)水平的变化并探讨与代谢综合征的关系。方法　选择 15 3例肥胖患者和 4 7例正常体重者 ,测定血清CRP水平 ,同时检测体重指数 (BMI)、腰围 (W )、腰臀比 (WHR)、血压、糖脂代谢参数、空腹胰岛素 (FIN)、胰岛素原 (PI)、胰岛素原 /胰岛素比值 (P/I) ,并对导致血清CRP改变的因素进行相关分析研究。结果　 ( 1)肥胖组血清CRP高于体重正常组 (P <0 .0 0 1) ,单纯肥胖组与肥胖伴糖代谢异常组之间无明显差异 (P =0 .4 13 ) ;( 2 )肥胖组相关分析显示血清CRP与W、WHR、SBP、TG、PI、HOMA IR、P/I呈正相关 ;( 3 )矫正年龄和BMI后 ,血清CRP与SBP、WHR和RI仍存在相关性 ,与其他变量的相关性消失。结论　 1、肥胖患者血清CRP水平明显高于非肥胖者 ,与SBP、TG、HOMA IR呈正相关 ,提示肥胖患者血清CRP水平升高与代谢综合征、胰岛素抵抗有密切关系 ;( 2 )血清CRP水平与P/I也呈正相关 ,提示血清CRP升高与 β 细胞功能缺陷可能也有一定关系 ;( 3 )BMI、WHR、SBP和PI是血清CRP升高的主要相关因素