BIOLOGICAL ACTIVITY OF THE β NERVE GROWTH FACTOR: THE EFFECTS OF VARIOUS ADDED PROTEINS

—The biological activity of β nerve growth factor varies greatly when other proteins are added to the culture medium. We have found that the biological activity can vary by a factor of 7 in a bioassay using 9 day embryonic chick sensory ganglia by adding bovine serum albumin to the culture medium. Adding the α and γ subunits in the form of 7S nerve growth factor has no effect on the biological activity of the β nerve growth factor. On the other hand, cytochrome c has an intermediate effect. Most of the increase in the biological activity seen on the addition of other proteins seems to be due to the ability of the other proteins to keep β nerve growth factor in solution; i.e. to prevent its adsorption to the culture tubes. However, some of the increase may also be due to an interaction that causes an activation of the β nerve growth factor.     

SOME PHYSICAL PROPERTIES OF BOVINE ADRENAL MEDULLARY DOPAMINE β-HYDROXYLASE

(1) Dopamine, β-hydroxylase (EC 1.14.2.1) was purified from bovine adrenal medullae according to the method of Foldes , Jeffrey , Preston and Austin (1972). (2) The kinetics, pH optimum and the effect of Cu²⁺ ions on the purified enzyme were found to resemble those of the enzyme isolated by more involved procedures. (3) The sedimentation coefficient (s₂₀) of the homogeneous enzyme in 10 mM-phosphate buffer, pH 7·2, containing 0·1 M-NaCI was found to be 10·24 ± 0·12 (S.E.M. of 10 determinations). (4) The effect of pH on the mol. wt. of the enzyme was investigated and no large deviation was found from the native mol. wt. of 290,000 in the pH range 3·9 to 11·1. (5) The amino acid analysis of dopamine β-hydroxylase is presented, and is contrasted to that of chromogranin A purified from the same chromaffin granule lysate. (6) Treatment with either 8 M-urea or 0·1% (w/v) sodium dodecyl sulphate was found to dissociate the enzyme into three similar, non-active subunits, each of mol. wt. of the order of 100,000.     

A RECOMBINATION ASSAY OF HIGH MOLECULAR WEIGHT NERVE GROWTH FACTOR PROTEIN COMPLEXES

Abstract— The 7S Nerve Growth Factor (NGF) found in mouse is a protein composed of three dissimilar subunits designated α, γ, and β. Mouse NGF reversibly dissociates into its component subunits at pH values lower than 5 or greater than 8. The 7S protein complex is in fast equilibrium wiih the free subunits. A quantitative determination of 7S NGF based on the reversible dissociation of the molecule into its subunits is reported here. The basis for this procedure is the addition of [¹²⁵I]α subunit which competes with the native alpha in the 7S complex. The level of NGF present in a sample can be measured in terms of the displacement of [¹²⁵I]α from the α to the NGF position in a linear sucrose gradient. Measurements are sensitive to 3.5ng of NGF, linear, and specific for the NGF molecule. This exchange is unaffccted by competing unrelated growth factors and inhibiting enzymes. Its specificity was checked by the standard bioassay and by radioimmunoassay. In addition, the assay technique overrides masking by biological inhibitors and/or by the presence of antibodies directed against the IgG contaminant in murine 75 NGF.     

7S NERVE GROWTH FACTOR PROTEIN IN THE GOLDEN HAMSTER

Abstract– Levels of 7S nerve growth factor in various tissues of the Golden Hamster were measured using a new assay procedure. The assay consisted of labelling native 7S nerve growth factor by allowing an ¹²⁵I-labelled subunit ([¹²⁵I]-α) of 7S nerve growth factor to compete with the native a subunit. The presence of 7S nerve growth factor was noted in a wide variety of non-neuronal and neuronal tissues. Levels of 7S nerve growth factor in the CNS decreased as the distance from the metencephalon increased both rostrally and caudally.     

河蚌C-反应蛋白的分离纯化及其性质研究

用合成的CDPC-Sepharose-6B亲和层析吸附剂一步提纯河蚌C-反应蛋白(CRP)。纯化的CRP在SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)和等电聚焦电泳鉴定时均显示为一条区带。其等电点(pI)为5.2,分子量约为310,000道尔顿,由六个亚基组成,亚基分子量约为51,000道尔顿。在280nm处的消光系数E_(1cm)~(1mg)/ml=1.2。河蚌CRP与C_多糖(CPS)发生的沉淀反应是钙依赖性的。本文对河蚌CRP的氨基酸组成及其它性质也作了研究。     

THE EFFECT OF β,β''-IMINODIPROPIONITRILE AND ANAESTHESIA ON SOME ADENINE NUCLEOTIDES OF RAT BRAIN AND RETINA

—A significant increase in the retinal ATP content of anaesthetised rats was found 6 days after administration of β, β′-iminodipropionitrile (IDPN). With the development of retinal dystrophy variable ATP levels were observed from the 8th to the 12th day and low values were recorded on the 17th and 21st days. At 8 days after IDPN administration the ATP content of anaesthetised rat brain was significantly increased with slight decreases in ADP and AMP levels. The differences in the level of these adenine nucleotides in unanaesthetised and anaesthetised rat brain were not significant before or after IDPN administration. These results were related to previous experiments on the action of IDPN on the electroretinal response and the later development of a retinal microangiopathy. It was suggested that IDPN has a primary neurotoxic effect followed by the development of vascular morphological changes.     

免疫酶双重染色法显示再生神经中的神经生长因子与睫状节神经营养因子

本研究以成人正中神经切割伤后２～３个月的神经干为材料,冰冻切片,用免疫双重染色技术显示了神经生长因子与睫状节神经营养（诱向）因子在再生的周围神经组织中的表达与分布。神经生长因子选用ＡＰＡＡＰ法．其阳性产物呈红色;睫状节神经营养（诱向）因子选用ＡＢＣ系统,４氯－１－萘酚显色,阳性产物为褐色。光镜下观察：神经生长因子的阳性反应产物出现在正中神经切割伤后再生的神经纤维中,高倍镜下可见其阳性产物分布在轴索,而在雪旺氏细胞中没能见到呈红色的阳性反应产物;睫状节神经营养（诱向）因子分布在一些细胞体积大、核大呈增生活跃状态的雪旺氏细胞中。红与褐双色反应产物色调清晰,效果较好。研究结果提示：睫状节神经营养（诱向）因子与神经生长因子在人周围神经再生过程中起着十分重要的作用。     

CHARACTERISTICS OF THE PURIFIED NERVE GROWTH FACTOR ANTIBODY

Purified nerve growth factor antibody has been shown to be competent in several different systems. The material is effective in producing immunosympathectomy in young rats and in preventing the action of nerve growth factor on explants of rat superior cervical ganglia. When injected into the brain of young rats it is without effect on brain tyrosine hydroxylase activity, but appears to escape into the system and cause a reduction of tyrosine hydroxylase activity in the superior cervical ganglia. Iodinated antibody injected subcutaneously into neonatal rats does not enter the brain and does not accumulate in superior cervical ganglia, or any of the other tissues studied. The antibody prevents the retrograde transport of nerve growth factor from the anterior chamber of the eye to the superior cervical ganglion and is not itself transported.     

PROPERTIES OF ACID β-d-GALACTOSIDASE ISOLATED FROM I-CELL DISEASE BRAIN AND SPLEEN

Abstract— Acid 4-methylumbelliferyl β- d -galactosidase activity from autopsied I-cell disease brain and spleen tissues was 28% and 35% respectively of normal activity. Acid β- d -gatactosidase (β- d -galactoside galactohydrolase, EC 3.2.1.23) from two I-cell disease brains demonstrated a 5-fold increase over normal for the proportion of enzyme activity which did not adsorb to Concanavalin A-Sepharose 4B, while acid β- d -galactosidase from two I-cell disease spleens demonstrated a 21–35-fold increase in the proportion of unadsorbed enzyme activity. Normal and I-cell disease acid β- d -galactosidase present in crude brain and spleen supernatant fluids and in preparations partially purified on Concanavalin A-Sepharose 4B had similar apparent K _m values with respect to 4-methylumbelliferyl β- d -galactopyranoside and G_M1-ganglioside. Isoelectric focusing profiles of normal and I-cell disease acid β- d -galactosidase from crude brain and spleen-supernatant fluids and partially purified preparations were similar. Neuraminidase treatment and subsequent isoelectric focusing of the partially purified normal and I-cell disease enzyme preparations from brain and spleen revealed increases in the proportion of I-cell β- d -galactosidases found at neutral pH values, suggesting that the electrophoretic variations observed for the I-cell enzymes may not be attributed solely to changes in sialic acid composition.     

PURIFICATION OF NERVE GROWTH FACTOR ANTIBODIES BY AFFINITY CHROMATOGRAPHY

Pure antibodies to nerve growth factor have been isolated from sheep nerve growth factorantiserum by affinity chromatography using 2.5 S nerve growth factor linked to Sepharose 4B by means of cyanogen bromide. The elution of the antibodies was accomplished either at low pH (pH 2) or by high salt concentration (4.5 wMgC12). The purity of the antibodies was established by SDS-gel electrophoresis. Their immunological activity was tested by imrnunoprecipitation and their biological activity in a tissue culture assay using embryonic chick dorsal root ganglia.     

神经生长因子促进坐骨神经再生修复的酶组织化学研究

目的研究对兔右坐骨神经损伤后局部给予蛇毒神经生长因子(NGF),观察坐骨神经酶活性变化和超微结构的恢复情况,探讨NGF对神经再生的影响.方法乙酰胆碱酯酶(AChE)、酸性磷酸酶(ACPase)的酶组织化学技术和电镜技术.结果神经损伤后:AChE活性明显下降,NGF组的AChE活性恢复快于盐水对照组;ACPase活性逐渐增高,NGF组的ACPase活性恢复时间短于盐水对照组.坐骨神经的超微结构在神经损伤后也发生变化,NGF组的变化程度小于盐水对照组,恢复时间短于对照组.结论NGF可通过影响酶物质的代谢而起到加快受损神经恢复的作用.为临床上应用蛇毒NGF治疗周围神经损伤提供形态学依据.     

棕色固氮菌钼铁蛋白结晶及一些物理化学性质

获得了棕色固氮菌固氮酶钼铁蛋白的针状结晶,大小为2-2.5×25-65微米,成晶所要求的条件不是很严格的。SDS 电泳和氨基酸分析结果表明,钼铁蛋白分子量为250,000。只观察到一种类型亚单位。其中酸性氨基酸占优势。分子氧使针状晶体演变为发状晶丝,晶丝又密集成束。晶束可保存较长时间。氧使钼铁蛋白在电泳时形成高聚合态。       

SOME PROPERTIES OF THE YEAST YELLOW PROTEIN

The yeast yellow protein contains two prosthetic groups, one of which is undoubtedly a flavin. The nature of the other is unknown, though some of its properties are described. No catalytic function for this protein has as yet been found.     

SOME PROPERTIES OF A MAJOR STRUCTURAL GLYCOPROTEIN OF SCIATIC NERVE

The major protein of rat sciatic nerve is a glycoprotein which consists of a protein moiety attached to galactose, mannose and perhaps other sugars. On controlled tryptic digestion, it splits into a glycopeptide and a smaller fragment similar in molecular size to peripheral nerve basic proteins. Both the basic proteins of peripheral nervous system (PNS) myelin and the glycoprotein are antigenically active when administered to guinea pigs and produce sciatic nerve lesions similar to those described for experimental allergic neuritis. It is suggested from the amino acid analysis and its antigenic properties that the protein moiety of the glycoprotein may contain a sequence which is similar to the basic proteins of PNS myelin.     

PURIFICATION AND SOME PROPERTIES OF S-100 PROTEIN FRACTIONS FROM SHEEP AND PIG BRAINS

Abstract— The S-100 protein fraction of pig and sheep brain was purified in 40 per cent yield by a modification of the procedure of M oore (1965), which avoided selective loss of S-100 components. The S-100 fraction of both pig and sheep is a mixture of proteins as indicated by acrylamide gel electrophoresis and N -terminal amino acid analysis. Differences in amino acid composition, electrophoretic heterogenity and N -terminal analysis were found.
One fraction (fraction A) was isolated by DEAE-Sephadex chromatography from pig brain S-100 protein fraction. It was considered to be a single protein since it migrated as a single band on acrylamide gel electrophoresis and showed a single symmetrical peak during ultracentrifugal analysis. Only one N -terminal amino acid was detected in fraction A. The amino acid composition of this fraction showed minor but significant differences from that of the complete S-100 protein fraction from pig brain. The S-100 protein fraction of both species, as well as fraction A, had similar s _{20, w} values and similar molecular weights (about 20,000) as indicated by gel filtration. These results, together with the immunological data obtained by other authors, suggest that the proteins of the S-100 fraction are closely related; the heterogeneity of the S-100 protein fraction may be of the same type as the lactate dehydrogenase isoenzymes.     

NERVE FIBER OUTGROWTH FROM DORSAL ROOT GANGLIA: ION DEPENDENCY OF NERVE GROWTH FACTOR ACTION

Abstract– Embryonic sensory neurons have an absolute requirement for the nerve growth factor to survive and grow fibers, at least in vitro . We have now shown that the inorganic cations, magnesium and potassium are also necessary for the survival of these cells. On the other hand, calcium is not needed for the survival of the sensory neurons, but is needed for the neurons to grow fibers. Therefore, by changing the concentration of calcium ions in the culture medium it is possible to separate the two actions (survival and fiber outgrowth) of the nerve growth factor on sensory neurons.     

NERVE GROWTH FACTOR AND THE ACTIVITY OF TYROSINE HYDROXYLASE IN ORGAN CULTURES OF RAT SUPERIOR CERVICAL GANGLIA

Abstract— Superior cervical ganglia from young rats were cultured in the absence of serum. The effect of nerve growth factor on the level of tyrosine hydroxylase was studied. In the absence of nerve growth factor the specific activity of tyrosine hydroxylase fell by more than 50% within 48 h. In the presence of nerve growth factor the total and specific activities were maintained and even increased in the same period. Both the 2.5 S and the 7 S forms of nerve growth factor were effective. Oxidized nerve growth factor had no effect except when present in very high concentration. Purified antibody to nerve growth factor was inhibitory. Insulin had only a slight effect in this system, but dibutyryl CAMP elevated tyrosine hydroxylase activity substantially. Propranolol inhibited the action of nerve growth factor but its action appeared to be nonspecific and unrelated to its action on the β-adrenergic receptor. Changes in the activity of dihydropteridine reductase paralleled those seen in tyrosine hydroxylase.