ISOLATION AND CHARACTERIZATION OF CYANOGEN BROMIDE FRAGMENTS OF THE A AND B CHAINS OF THE ANTITUMOR TOXIN RICIN D

Both the A and B chains of ricin D consist of four CNBr fragments. These fragments have been isolated from the separated chains of S-carboxymethylated ricin D obtained from the small bean variety of Ricinus communis. The peptides have been characterized by molecular weight, amino acid composition and amino terminal sequence. A unique order of the peptides is evident for each chain. These sequence data are compared with those obtained for ricin D isolated from the large bean variety (Funatsu et al, 1979; Yoshitake et al., 1978).     

SEQUENCE OF CYANOGEN BROMIDE FRAGMENTS D AND E OF B. AMYLOLIQUEFACIENS ALPHA AMYLASE

Alpha amylase (Sigma type IIA) was cleaved by cyanogen bromide. The sequences of two fragments, D which contains 88 amino acids and E which contains 56, are presented. By applying the Chou-Fasman rules, D is predicted to have 32% beta sheet and 37% alpha helix, and E is predicted to exhibit 11% beta sheet and 71% alpha helix.     

ISOLATION AND PARTIAL SEQUENCE OF THE CYANOGEN BROMIDE PEPTIDES FROM CALF THYMUS NON-HISTONE CHROMOSOMAL PROTEIN HMG 1

Peptides produced by cyanogen bromide cleavage of non-histone chromosomal protein HMG 1 have been isolated and characterized, and their partial sequences determined. The sequence data presented here account for over half of the sequence of the HMG 1 molecule and, together with previously published results, provide interesting information on the charge distribution within the molecule.     

SHORT DIGESTION OF BOVINE SERUM ALBUMIN WITH PEPSIN. ISOLATION AND CHARACTERIZATION OF FRAGMENTS AND THEIR LOCATION IN THE ALBUMIN MOLECULE

After short peptic digestion of bovine serum albumin between pH 3.6 and 3.9, a limited number of well defined fragments are found. The isolation and characterization of some fragments, probably placed in the C-terminal part of albumin, have been given in a previous paper. This paper describes the isolation, characterization and localization of a number of N-terminal fragments of bovine serum albumin. The investigation comprises molecular weight determination, amino acid analysis, N-terminal amino acid determination, copper binding studies and SH-group determination. It is concluded that cleavage of albumin by pepsin between pH 3.6 and 3.9 preferentially occurs in the C-terminal moiety of albumin. This leads to the appearance of large fragments with the same N-terminal end as albumin. The mechanism of the digestion by pepsin is discussed in relation to the structural model of albumin and the conformational change at low pH (N-F transition).     

ISOLATION AND CHARACTERIZATION OF THREE LUTROPIN ISOHORMONES FROM THE PITUITARY GLAND OF THE OSTRICH (STRUTHIO CAMELUS)

Avian lutropin has been isolated from pituitary glands of the ostrich (Struthio camelus) in three homogeneous forms (designated isohormones). The different homogeneous forms of ostrich lutropin were characterized physically and chemically in terms of molecular weight, electrophoretic mobility, isoelectric points, amino acid and carbohydrate composition. From these characteristics it was evident that the isohormones are very similar. The differences between these isohormones can be attributed to differences in carbohydrate composition, especially sialic acid.     

ISOLATION AND CHARACTERIZATION OF GONADOTROPIN ISOHORMONES FROM THE PITUITARY GLAND OF PIKE EEL (MURAENESOX CINEREUS)

Pike eel gonadotropins were isolated from pituitary glands by 40% alcohol-6% ammonium acetate, pH 5.1 extraction and were purified by DEAE-cellulose chromatography and electrophoresis into four electrophoretically homogeneous forms. These four isohormones were biologically identified as gonadotropins by the stimulation of ³²P-uptake in 1-day-old chick testes, by the induction of ovulation in catfish, and by the in vitro production of testosterone from isolated rat Leydig cells and of androgen from carp testes. The amino acid composition of the isohormones were similar to other known piscine gonadotropins (carp and salmon) and were composed of two non-identical subunits with Tyr and Ser as N-terminal amino acid residues. The molecular weights of two subunits were 15 000 and 10 500, respectively, as estimated by SDS-gel disc electrophoresis.     

ISOLATION AND CHARACTERIZATION OF ALPACA GROWTH HORMONE

A simple and mild procedure is described for the isolation of pituitary growth hormone from alpaca glands. It involves extractions in buffer at pH 8. 7 and gel filtration in Sephadex G-75. An average yield of 1 mg purified product may be obtained from 1 g fresh alpaca pituitary glands. The alpaca hormone was exam ined for homogeneity by SDS-polyacrylamide gel electrophoresis, gel electro-focusing and end-group analyses. It is a protein composed of a single polypeptide chain with phenylalanine at both ends. The C-terminal sequence is -Ala-Phe. The molecular weight is approximately 21700 and the amino acid composition very similar to that observed in equine growth hormone.     

ISOLATION AND PROPERTIES OF TWO FRAGMENTS FROM PLASMIN DIGESTS OF HUMAN CHORIOMAMMOTROPIN

Two fragments have been isolated and characterized from plasmin digests of human choriomammotropin. It was shown that these two fragments were derived from the cleavage of the Arg-Arg (positions 133–134) and the Lys-Gln (positions 140–141) bonds of the hormone: one has 133 amino acids and the other 51 amino acids. Both fragments were biologically and immunologically inactive.     

ISOLATION AND PHYSICAL CHARACTERIZATION OF BOVINE LENS CRYSTALLINS

The soluble proteins from bovine lens homogenate were separated on Sepharose CL-6B (2 times 200 cm) in 0.05 m tris-NaHSO₃ pH 8.2 buffer containing 20 mM EDTA. Five sharp and defined fractions (HMα, α, βH, βL, γ) were obtained. Each crystallin fraction was further purified by rechromatography on the same column. Each protein fraction was pure as judged by ultracentrifugation and SDS-gel electrophoresis. The molecular weights of the five fractions were 3.04 times 10⁶, 5.83 times 10⁵, 1.58 times 10⁵, 4.59 times 10⁴, 2.14 times 10⁴ as determined from sedimentation coefficient and intrinsic viscosity data by Scheraga-Mandelkern equation, which was in close agreement with that obtained by gel filtration. The polypeptide composition of crystallins as determined by SDS-gel electrophoresis revealed one band for high molecular weight α (HMα) and α, three for βH, two for βL and one for γ. The gross CD patterns of crystallins were about the same in the peptide region (200 nm ? 250 nm) with a minimum centered at about 217 nm, indicative of α β-sheet structure in all crystallins. The [0] values at 217 nm ranged from –1700 to –3700 degrees cm² per decimole. The CD spectra of these crystallins in the aromatic region (250 nm ? 300 nm) were different, reflecting the different contributions of aromatic amino acids to the tertiary structure of crystallins.     

ISOLATION AND CHARACTERIZATION OF FIN WHALE PROLACTIN*

A highly purified prolactin preparation has been obtained from fin whale pituitaries by extraction with acid acetone, salt precipitation, isoelectric fractionation, and exclusion chromatography on Sephadex G-100 and ion-exchange chromatography on DEAE-cellulose. Fin whale prolactin was isolated in a yield of 250 mg/kg wet weight tissue. It was found to have a molecular weight (SDS disc gel electrophoresis) of 23,600 daltons and an α-helix content (circular dichroism) of 50%. The amino acid composition and circular dichroism spectra were very similar to those of porcine prolactin. The partial amino acid sequence has been determined by the method of fluorescein-isothiocyanate. Fin whale prolactin was found to be 80% as potent as ovine prolactin with regard to pigeon crop-sac assay.     

细胞分裂素产生菌质粒DNA的分离和鉴定

本文首次报道从细胞分裂素产生菌泾阳链霉菌A_3中分离得到两种质粒,并经电镜观察得到了证实。琼脂糖凝胶电泳分析,表明质粒DNA的分子量分别为4.8×10~6道尔顿(7.3kb)和3.4×10~6道尔顿(5.7kb),并命名为pSJ_1、和pSJ_2。快中子消除质粒处理,得到的无质粒菌株(B_(11))与原株(A_3)比较,两者在培养特征方面没有差异,但在产生细胞分裂素及硝酸盐还原酶方面存在差异。菌株B_(11)的细胞分裂素产量和酶活性高于和显著高于原株A_3。结果表明,质粒pSJ_1和pSJ_2可能携带调控细胞分裂素生物合成及硝酸盐还原酶的某些基因。     

ISOLATION AND CHARACTERIZATION OF HIGHLY PURIFIED ALPHA-1-ANTITRYPSIN

Highly purified human alpha-1-antitrypsin (phenotype MM) was obtained by an original method of preparative electrophoresis. The criteria of homogeneity were assured by one arc in crossed immunoelectrophoresis and one band on polyacrylamide gel. A unique N-terminal amino acid (pyroglutamic acid) and a unique C-terminal residue (lysine) were identified. Determined by gel electrophoresis, its molecular weight was 47,000 daltons.     

(-)棉酚和(+)棉酚对蛋白激酶C及蛋白激酶A活力影响的比较

部分纯化的大鼠肝脏蛋白激酶C和蛋白激酶A,在体外与棉酚的旋光异构体分别温育,结果(--)棉酚和(+)棉酚对蛋白激酶C活力均有剂量依赖性的抑制作用;(-)棉酚对Ⅰ型蛋白激酶A活力的抑制作用明显比(+)棉酚强,而(-)棉酚和(+)棉酚在高浓度时对Ⅱ型蛋白激酶A才显示抑制作用。结果提示棉酚在体内可能干扰细胞信息的传递过程。     

雷酚萜醇的分离和结构

雷公藤(Triplerygium wilfordii Hook.f.)系卫矛科(Celastzaczae)雷公藤属植物。从雷公藤根中分得雷公藤内酯醇(triptolide)对实验肿瘤有较强的抑制作用,临床试用治疗白血病有一定的疗效。为了寻找低毒有效的类似物,作者进行雷公藤中共它二萜成分的研究。前报报道从福建泰宁县产雷公藤中分离得三种新二萜——雷酚萜(triptonoter-     

平阳霉素的分离和鉴别

轮枝链霉菌平阳新变种(Str.Verticillus Vat.Pingyangensis n.Var.)所产生的抗肿瘤抗菌素是由十余种组分组成的复合物,其中两个主要组分分别与博莱霉素A₂和B₂完全相同。在生产过程中通过菌种选育和发酵工艺的改进,产品的组成发生了变化,主要组分变成了博莱霉素A₅,已正式命名为平阳霉素。它在复合物中所占比例一般约为60%。本文报告平阳霉素的分离、理化性质和鉴别。     

ISOLATION AND CHARACTERIZATION OF β-LIPOTROPIN FROM THE PITUITARY GLAND OF THE OSTRICH,STRUTHIO CAMELUS

Avian β-lipotropin (β-LPH) was purified from adenohypophyseal glands of the ostrich Struthio camelus by a procedure involving acid/acetone extraction, NaCl fractionation, CM-cellulose chromatography, Sephadex G-75 chromatography and paper electrophoresis (pH 6.7). The 90-amino acid peptide behaved as a single substance during polyacrylamide-gel electrophoresis, isoelectric focusing (pI of 6.0) and N-terminal analysis, the N-terminal amino acid being alanine. Ostrich β-LPH exhibited lipolytic activity corresponding to an average minimal effective dose of 0.088 μg in rabbit adipose tissue.     

绛红色小单孢菌烈性噬菌体Mph1的分离及其特性

从庆大霉素产生菌——绛红色小单孢72~#异常发酵液中分离到一株烈性噬菌体,能裂解绛红色小单孢菌,形成清晰的噬菌斑,直径2mm左右,侵染指示菌的潜伏期为2小时,增殖期为1.5小时,当pH小于3或大于10及温度高于60℃时明显失活.用限制性内切酶酶解噬菌体发现有EcoRⅠ、HindⅡ、BamHⅠ、SaIⅠ切割位点,DNA分子量约为30kb,电镜观察表明该噬菌体有一六角形头部和一短尾部。     

PURIFICATION AND CHARACTERIZATION OF THE SURFACE ACTIVE PROTEINS OF BLACK GRAM (PHASEOLUS MUNGO)

The surface active globulin from black gram has been resolved into two components with high foam-forming activity. They were found to be homogeneous by electrophoresis and ultracentrifugal examinations and had high molecular weights around 100,000 daltons. They were rich in acidic as well as basic amino acids but low in sulphur amino acids. Heat treatment, proteolysis and treatment with certain inorganic salts such as copper, and mercurous mercury, group specific reagents P-chloromercury benzoate and N-ethylmalemide (PCMB, NEM) and protein denaturants were found to have an adverse effect, while oxidizing agents had no effect. The free sulphydryl content was low (3 and 4 μmol/mol), but essential for full manifestation of surface activity. Other purified proteins also needed free sulphydryl groups.     

刺梨酸的分离与结构研究

从刺梨中分离出一种新的五环三萜酸,命名为刺梨酸。通过光谱分析和衍生物的制备,确定其化学结构为2β,3α,7β,19α-四羟基乌苏-12-烯-28-羧酸。