Clostridium molecular weight

It has been postulated that Chlamydia may produce a heat shock protein that causes tissue damage through a delayed hypersensitivity reaction. C. trachomatis may also possess DNA evidence of toxin-like genes that code for high-molecular-weight proteins with structures similar to Clostridium difficile cytotoxins, enabling inhibition of immune activation. This may explain the observation of a chronic C. trachomatis infection in subclinical PID. 

The crystallographic structure of rubredoxin from Clostridium pasteurianum at 2.5 A, a resolution sufficient to reveal the sequence of several of the bulky amino acid side chains, shows the iron coordinated to two pairs of cysteine residues located rather near the termini of the polypeptide chain (Fig. 1). A related rubredoxin, with a three times larger molecular weight, from Pseudomonas oleovorans is believed to bind iron in a similar fashion. This conclusion is based on physical probes, especially electron paramagnetic resonance spectroscopy, all of which indicate that the iron is in each case situated in a highly similar environment however, the proteins display some specificity in catalytic function. 

Macmillan and coworkers51 105 106 purified pectinesterase produced by Clostridium multifermentans by using practically all of the available methods and materials (calcium phosphate gel, DEAE-cellulose, DEAE-, QEAE-, CM-, and SE-Sephadex, Sephadexes G-75, G-100, G-150, and G-200, Sepharose 4B, and zonal centrifugation). However, they could not separate pectinesterase from exo-pectate lyase, and, hence, they postulated that either (a) a complex of the two enzymes having an apparent molecular weight of 400,000 exists, or (b) the two enzymes are identical in their molecular species. On the basis of the mode of action of this pectinesterase in comparison with that of those from tomatoes and from Fusarium ox-ysporum, the existence of a complex of pectinesterase and exopectate lyase in Clostridium multifermentans appears to be the more probable. 

The highest degree of purification was achieved with extracellular endopectate lyase from the anaerobic bacterium Clostridium fel-sineum.Mi A 225-fold purified preparation, homogeneous in disc electrophoresis, was obtained by precipitation with ethanol, and chromatography on CM-cellulose and on Sephadex G-200. Its molecular weight (determined by gel chromatography) was 105,000. 

Das A, Coulter ED, Kurtz DM, Jr, Ljungdahl LG. 2001. Five-gene cluster in Clostridium thermo aceticum consisting of two divergent operons encoding rubredoxin oxidoreductase— rubredoxin and rubrerythrin— type A flavoprotein— high-molecular-weight rubredoxin. J Bacteriol 183 1560-7. 

Rubredoxins. Rubredoxins are the simplest form of iron-sulfur proteins in which iron is bound to the sulfur atom of cysteine as shown in Fig. lA. One of the first rubredoxins isolated was from an anaerobic bacterium, Clostridium pasteurianum, by Lovenberg and Sobel (9). The protein is composed of 54 amino acids and has a molecular weight of 6,000. The oxidized form has absorbance maxima at 380 and 490 nm. The biological role of the rubredoxin isolated from C. pasteurianum is stiU unknown. 

Nicotinic acid hydroxylase from Clostridium barkerii catalyzes reaction (55), the hydroxylation of a pyridine group, and has similarities to xanthine dehydrogenase. Nicotinic acid hydroxylase is a 300 000 molecular weight flavoprotein containing iron-sulfur and FAD centres, selenium1034 and a molybdopterin cofactor.1035 Formate dehydrogenase contains selenium as selenocysteine,1036 but this does not appear to be the case for nicotinic acid hydroxylase. The possibility that the selenium is incorporated into the molybdopterin cannot be excluded at present. 

This protein contains two types of subunit of molecular weights 50 000 and 60 000, with an overall arrangement otiPi- The total molecular weight is thus in the range 220000-245 000, depending upon the source (A. vinelandii,1473 Klebsiella pneumoniae1474 and Clostridium... 

The bacterial-type iron-sulfur proteins all contain larger amounts of iron and labile sulfide than the plant-type iron-sulfur proteins best estimates for the iron and labile sulfide content being 8 Fe and 8 S per protein molecule (172, 173) for these ferredoxins from Clostridium and from Chromatium. Although these proteins have large amounts of Fe and S, the molecular weights are less than the molecular weights of the... 

Rubredoxin is a small protein which has one Fe ion (molecular weight 6000), as is schematically illustrated in Fig. 3. Jensen s group has revealed fairly precise structural features of the active site of Clostridium pasteurianum and Desulfovibrio vulgaris rubredoxins (10, 11). The simple model complex [Fe(S2-o-xyl)2], 2 has been synthesized and analyzed crystallographically by Holm s group (12). Geometry of the FeS4 core of the oxidized rubredoxin seems to be almost identical to that... 

Botulimun toxin is derived from the gram-negative bacterium Clostridium botulinum, an anaerobic rod that is commonly known as the source of an extremely harm-fiil food-borne toxin. Although a number of different serotypes of toxin have been identified, serotype A is used in the commercially available drug Botox, or Oculinum. It is a high-molecular-weight protein that is supplied in a freeze-dried form requiring reconstitution with saline before injection. 

Dove CH, Wang SZ, Price SB etal. (1990) Molecular characterization of the Clostridium difficile toxin A gene. In Infect. Immun. 58 480—8 Eichel-Streiber C, Harperath U, Bosse D etal. (1987) Purification of two high molecular weight toxins of Clostridium difficile which are antigenetically related. In Microb. Pathogen. 2 307-18... 

An effective variant of the gas injection EOR procedure is the proposal to inject molasses or some other low-cost fermentable material plus a species of bacterium, such as Clostridium acetobutylicum into the formation [21]. Eer-mentation products, such as acetone, butanol, and lower molecular weight acids are produced. These and the carbon dioxide also produced can augment production by 200-250%. 

Rudnick and Abeles purified proline racemase to 95% homogeneity from Clostridium sticklandii, and characterized it 92. The enzyme is composed of two identical subunits with a molecular weight of about 38000, and is independent of any cofactors or metals. Most amino acid racemases require pyridoxal 5 -phosphate, which labilizes the bond between the a-hydrogen and the chiral center by aldimine formation with the a-amino group of the substrate. However, PLP is not involved in the reaction of proline racemase acting on an a-imino acid. The enzyme also acts on 2-hydroxy-L-proline and 2-allo-hydroxy-D-proline although slowly they are epimer-ized at a rate of 2 and 5% of the rate of L-proline racemization, respectively. L-Proline and D-proline showed Km values of 2.9 and 2.5 mti, respectively1119. ... 

Botulism — Clostridium botulinum toxin is composed of polypeptides or proteins designated A throngh G with molecular weights of 200,000 to... 

The species Clostridium perfingens has heat-labile protein enterotoxin and a molecular weight of about 36,000. Botulism toxin is in fact... 

A ferredoxin with a molecular weight of 6000 and seven atoms of iron per molecule was extracted from Clostridium pasteurianum and oxidised samples show similar spectra [29], although with some evidence for at least two iron environments. An S = i configuration was proposed, but the confirmatory experiment of applying a magnetic field and looking for magnetic effects has not yet been carried out. 

By far the most well studied enzyme catalyzing a decarboxylation reaction in which iminium ion formation is involved, is acetoacetate decarboxylase [79]. This enzyme obtained from Clostridium acetobutylicium [80] has an apparent molecular weight of approximately 340000, and is composed of subunits with a molecular weight of 29000 [81], It is apparently composed of 12 subunits, and these may be dissociated... 

---