Dodecyl Sulfate-polyacrylamide Gel Research Articles

Identification of New Zealand grown barley cultivars by grain characters

Abstract Laboratory methods of barley (Hordeum vulgare L.) identification by grain characters were evaluated. These included categorisation by: morphological characters of grain shape, furrow hairs, grain base shape, rachilla length, rachilla type, and presence or absence of lemma teeth; reaction to phenol; sodium dodecyl sulphate (SDS) poly-acrylamide gel electrophoresis for hordeins; gradient gel electrophoresis for hordeins; and gradient gel electrophoresis of peroxidase isozymes. Of the 20 cultivars evaluated, ‘Makareta’, ‘Liberty’, ‘Triumph’, ‘Universe’, ‘Hassan’, ‘Priver’, ‘Kakapo’, and ‘Illia’ were uniquely described by morphological characters. Of the remainder, only ‘Mata’, ‘Goldspear’, and ‘Magnum’ could not be separated by the phenol test, but these cultivars could be distinguished by at least two of the electrophoretic techniques.

Purification and properties of 1-phosphofructokinase from Escherichia coli

1-Phosphofructokinase has been purified from Escherichia coli. Size exclusion chromatography revealed an Mr of 57000. After sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) we found a single protein band corresponding to an Mr of 30000. The enzyme was highly specific for fructose-1-phosphate. ATP and GTP were the best phosphoryl donors, whereas UTP and CTP showed only a weak effect. The enzyme was reversibly inhibited by fructose-1, 6-bisphosphate and ADP and irreversibly by phenyl-methanesulfonyl fluoride (PMSF). ATP prevented irreversible inhibition by PMSF. Fructose-1-phosphate had a much less pronounced effect on irreversible inhibition by PMSF. Comparison of the peptide map of tryptic digested 1-phosphofructokinase and PMSF-modified 1-phosphofructokinase revealed an additional peak for the modified 1-phosphofructokinase whereas the intensity of another peak was lowered compared to untreated 1-phosphofructokinase. This peptide might therefore represent the binding site for ATP.

Affinity purification of alkylglycerol monooxygenase from rat liver microsomes by chimyl alcohol-Sepharose 4B column chromatography.

Alkylglycerol monooxygenase of rat liver microsomes was purified approximately to 97-fold with a 30% yield by procedures including affinity chromatography on chimyl alcohol-Sepharose 4B. Chimyl alcohol (1-O-hexadecylglycerol) was converted to the p-aminobenzylidene derivative and then coupled to 6-carboxyhexyl-Sepharose. The final enzyme preparation was in nearly a homogeneous state, judging from the results of sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis, and it migrated to a position corresponding to an apparent molecular weight of 45,000. The results revealed that the native form of the enzyme (estimated to have a molecular weight of 400,000 as judged by Sepharose 6B column chromatography in a previous report, Ishibashi, T., and Y. Imai. 1983. Eur. J. Biochem. 132: 23-27) will polymerize to large aggregates.

Characterisation of size variants of type I DNA topoisomerase isolated from calf thymus.

Calf thymus DNA topoisomerase I, which belongs to the eukaryotic type I topoisomerases, is in a typical preparation purified as a set of five major polypeptides with Mr between 70000 and 100000. At least four of these proteins have binding affinity for DNA as was shown by incubating them with radioactive single-stranded DNA after separation in dodecylsulfate polyacrylamide gels and blotting onto nitrocellulose filters. That these polypeptides have DNA relaxing activity was directly demonstrated with protein extracted from single bands of dodecylsulfate/polyacrylamide gels. We consider the 100000-Mr protein to be the native enzyme. The smaller components are catalytically active fragments of the native topoisomerase most probably arising from limited proteolysis either within the nucleus or during the purification of the enzyme. In two-dimensional non-equilibrium pH-gradient electrophoresis gels the topoisomerase size variants exhibit apparent pI values between 8.1 and 8.3, with small but distinct differences between the components. The calf thymus topoisomerase I, upon binding to phage fd-DNA, protects a stretch of 15-25 nucleotides against digestion with DNase I.

Isolation and characterization of trypsin inhibitors from tubers of taro, Colocasia antiquorum var. nymphaifolia?

Three trypsin inhibitors were isolated from tubers of taro (Colocasia antiquorum var. nymphaifolia?) and named taro trypsin inhibitors (TTI)-I, -II, and -III. The final preparations were homogeneous by polyacrylamide gel electrophoresis and sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The three inhibitors showed strong and stoichiometric inhibition against bovine trypsin and the inhibitor constants (Ki) were estimated to be of the order of 10(-9) to 10(-10) M. In contrast, they had only a weak capacity to inhibit bovine alpha-chymotrypsin and did not inhibit subtilisins (BPN' and Carlsberg), porcine pepsin, or papain. Each inhibitor appeared to be a protein with a molecular weight of 40,000 which could be dissociated into two subunits, both of which had a molecular weight of 20,000. The inhibitors formed complexes with trypsin at molar ratios of 1:2, suggesting that each subunit of these inhibitors can react with the enzyme in a 1:1 molar ratio. The three inhibitors had similar amino acid compositions and none of them contained carbohydrate or free sulfhydryl group. The antitryptic activity of all three inhibitors was suppressed by treatment with 1,2-cyclohexanedione (CHD) but not with 2,4,6-trinitrobenzenesulfonate (TNBS), thus demonstrating each of the inhibitors to contain an arginyl residue at the reactive site.

Lipid and Protein Composition of the Surface Tegument from Larvae of Taenia taeniaeformis

A tegumental fraction from fully developed larvae of Taenia taeniaeformis was recovered by low speed centrifugation following incubation of the parasites in a 0.1% solution of digitonin. Scanning electron microscopy of the parasite carcass revealed no surface microtrichs, and transmission electron microscopy indicated that the subtegumental layer was undamaged. The tegumental fraction, judging from the distribution of 3H-Concanavalin A, was enriched for surface components, exhibited low succinic dehydrogenase activity, and an electron microscopic examination of the pellet showed a slightly expanded but intact distal tegumental layer. The fraction, which made up 3.0% of the dry weight of the parasite, consisted of 52% protein and 32% lipid. Thirty-three proteins, ranging in Mr from 9,000 to 276,000 daltons, were detected after sodium dodecyl sulfate solubilization and polyacrylamide gel electrophoresis. Seven of these proteins were glycoproteins. Cholesterol, phosphatidylethanolamine, phosphatidylserine, and glycosphingolipids were the major lipids.

Synthesis of subunit III of CF0 by thylakoid-bound polysomes from pea chloroplasts

Wahsed thylakoid membranes from pea chloroplasts incorporate label from ((35)S)-methionine into protein when supplemented with S-30 soluble factors from E. coli. One of the products associated with the thylakoids is soluble in butanol, precipitated by ether and has an apparent molecular mss of 8200D on urea-lithium dodecyl sulphate (LDS) polyacrylamide gels. In addition, the protein covalently binds dicyclohexylcarbo-diimide (DCCD) which causes it to migrate as two slower forms on gels. Based on these criteria we establish that the proteolipid or subunit III of CF0 (the intrinsic sector of the ATPase complex) is synthesized by the thylakoid bound polysomes.

Macrozin, a Novel Storage Globulin From Seeds of Macrozamia communis L. Johnson

The isolation, characterization and amino acid composition are reported for macrozin, the major storage globulin found in seeds of Macrozamia communis. Electrophoresis of macrozin on cellulose acetate membranes at neutral pH resulted in a single broad band indicating limited charge heterogeneity. Isoelectric focusing under dissociating and reducing conditions showed this globulin to be composed of a family of polypeptide chains with apparent isoelectric points in the range pH 6.0-7.5. Sedimentation equilibrium studies showed that the main component purified by gel filtration in aqueous buffers at neutral pH has a molecular weight of 260 000 and a sedimentation coefficient S020.w = 10.9 S. This component dissociates in 8 M urea to yield subunits of molecular weight 126 000. Each subunit is composed of disulfide-bonded polypeptide chains of approximate molecular weight 44 000. The apparent molecular weights for the macrozin subunit and its constituent polypeptides were 130 000 and 46 000 from dodecyl sulfate-polyacrylamide gradient gel electrophoresis. The dimeric nature of the main oligomer in aqueous solution was confirmed by crosslinking the subunits with dithiobis(succinimidylpropionate); the presence of three polypeptide chains per subunit is inferred from the molecular weights. Optical rotatory dispersion and circular dichroism measurements suggest that macrozin is devoid of α-helix in its native conformation, but contains some 25% α-helix after incubation with sodium dodecyl sulfate.

Changes in Actin Content During Induced Myeloid Maturation of Human Promyelocytes

AbstractActin is an important cytoskeletal protein; new actin synthesis occurs during differentiation of many motile cells. To better understand the process of myeloid maturation, the change in actin content during induced maturation of HL-60 human promyelocytic leukemia cells was studied. HL-60 cells induced toward myeloid maturation by a 5-day exposure to dimethylformamide showed an 86% increase in a 43.000 mol wt protein comigrating with rabbit muscle actin on dodecyl sulfate polyacrylamide gels. To further demonstrate that this was an increase in actin content, the total actin content of lysed HL-60 cells was measured by the ability of actin to inhibit DNAase I. Using this assay, actin content of HL-60 cells increased 96% during induced differentiation. The amount of incorporation of 3H-leucine into actin doubled after a 5-day exposure to dimethylformamide, suggesting the increase in actin was due primarily to new synthesis. Total new protein synthesis increased 2–7-fold during differentiation. Additional analysis of polyacrylamide gels showed increased quantities and new synthesis of a high molecular weight protein comigrating with rabbit muscle myosin. This study shows that actin content increases during myeloid maturation. It also demonstrates that the HL-60 cell line is a useful model to study both functional and biochemical events during human myeloid differentiation.

Changes in actin content during induced myeloid maturation of human promyelocytes

Actin is an important cytoskeletal protein; new actin synthesis occurs during differentiation of many motile cells. To better understand the process of myeloid maturation, the change in actin content during induced maturation of HL-60 human promyelocytic leukemia cells was studied. HL-60 cells induced toward myeloid maturation by a 5-day exposure to dimethylformamide showed an 86% increase in a 43,000 mol wt protein comigrating with rabbit muscle actin on dodecyl sulfate polyacrylamide gels. To further demonstrate that this was an increase in actin content, the total actin content of lysed HL-60 cells was measured by the ability of actin to inhibit DNAase I. Using this assay, actin content of HL-60 cells increased 96% during induced differentiation. The amount of incorporation of 3H-leucine into actin doubled after a 5-day exposure to dimethylformamide, suggesting the increase in actin was due primarily to new synthesis. Total new protein synthesis increased 2–7-fold during differentiation. Additional analysis of polyacrylamide gels showed increased quantities and new synthesis of a high molecular weight protein comigrating with rabbit muscle myosin. This study shows that actin content increases during myeloid maturation. It also demonstrates that the HL-60 cell line is a useful model to study both functional and biochemical events during human myeloid differentiation.

Import of proteins into mitochondria. Isolated yeast mitochondria and a solubilized matrix protease correctly process cytochrome c oxidase subunit V precursor at the NH2 terminus.

The cytoplasmically made subunit V was isolated from enzymically active yeast cytochrome c oxidase and its NH2-terminal amino acid sequence was determined to be (formula; see text) In order to exclude that this NH2 terminus had been generated by proteolysis during the lengthy isolation of the subunit, subunit V was directly immunoprecipitated from yeast cells that had been pulse-labeled with [35S]methionine; radiochemical sequencing revealed methionine at position 12, in agreement with the sequence given above. When the precursor to subunit V was synthesized in vitro in the presence of either [35S]methionine, [3H]leucine, or [3H]histidine and then incubated either with isolated yeast mitochondria or the partially purified matrix protease (Böhni, P. C., Daum, G., and Schatz, G. (1983) J. Biol. Chem. 258, 4937-4943), it was converted to a polypeptide co-migrating with mature subunit V on dodecyl sulfate-polyacrylamide gels. Radiochemical sequence analysis of the processed in vitro product showed that it contained histidine, leucine, and methionine in positions 4, 6, and 12, respectively, exactly as the authentic mature protein. In contrast, the unprocessed precursor contained methionine only at position 9, but not at position 12; thus, the precursor has a NH2 terminus different from the mature polypeptide. Similarly, if the in vitro synthesized cytochrome b2 precursor is incubated with isolated mitochondria, it is converted to a polypeptide which co-migrates with mature cytochrome b2 and, like the latter, contains leucine and methionine in positions 4 and 6, respectively. These data show that isolated yeast mitochondria convert the precursors to polypeptides which have the NH2 terminus of the authentic mature polypeptides. In the case of cytochrome c oxidase subunit V, correct NH2-terminal processing was also demonstrated with the purified matrix protease.

Light-stimulated synthesis of NADP malic enzyme in leaves of maize.

Illumination of etiolated maize plants for 80 h brings about a 15-20-fold increase in activity of NADP malic enzyme (EC 1.1.1.40). Increases in NADP malic enzyme protein and in the level of translatable mRNA for this protein occur simultaneously with the activity increase. Radiolabeled amino acids are also incorporated into NADP malic enzyme during this time. These results are consistent with the conclusion that an increase in NADP malic enzyme activity during greening results from de novo synthesis of NADP malic enzyme protein. Polyadenylated RNA extracted from greening maize leaves directs the synthesis in vitro of a protein 12,000 daltons larger than NADP malic enzyme purified from corn leaves. This protein is a precursor of NADP malic enzyme because 1) both the precursor and mature NADP malic enzyme are immunoprecipitated by antibody made against NADP malic enzyme purified from corn leaves, 2) both NADP malic enzyme protein and the level of mRNA for the precursor increase during greening, and 3) peptide maps of the precursor and of mature NADP malic enzyme are very similar. Mature NADP malic enzyme and its precursor (synthesized in vitro) both migrate on sodium dodecyl sulfate-polyacrylamide gradient gels as doublet bands. Peptide analyses show all bands to be structurally related.

F1-like ATPase from anaerobic bacterium Lactobacillus casei contains six similar subunits.

Membrane‐linked ATPase of an anaerobic bacterium Lactobacillus casei has been studied.It was found that L. casei membrane particles hydrolyzed 0.1–0.2 μmol of ATP × mg protein−1× min−1 in the presence of Mg2+ or Ca2+ ions at optimal pH 6.4. This activity was inhibited by N,N′‐dicyclohexylcarbodiimide. Oligomycin, ouabain, vanadate and hydroxylamine were ineffective.The addition of valinomycin to the intact L. casei cells in the absence of extracellular K+ and glucose resulted in an ATP synthesis which was abolished by the addition of K Cl, N,N′‐dicyclohexylcarbodiimide or carbonylcyanide m‐chlorophenylhydrazone. In the presence of glucose, L. casei cells showed an energy‐dependent accumulation of tetraphenylphosphonium cations, which was sensitive to N,N′‐dicyclohexylcarbodiimide and carbonylcyanide m‐chlorophenylhydrazone.A soluble ATPase was isolated from L. casei membranes by means of (a) washing with a low ionic strength buffer in the presence of EDTA, Mg2+ ions and a protease inhibitor ‐ diisopropylfluorophosphate or (b) a chloroform treatment. Crude ATPase extracts were purified using isotachophoresis and (or) Sepharose 6B gelfiltration. Preparations of purified ATPase had a specific activity 3.0–4.0 μmol ATP × mg protein−1× min−1 and were homogeneous when studied with analytical disc electrophoresis or analytical ultracentrifugation (s20,w= 12 ± 0.5 S). The molecular mass of the L. casei ATPase estimated with sieve chromatography on Sepharose 6B proved to be 270 kDa. Purified L. casei ATPase denaturated by 1% sodium dodecyl sulphate or 8 M urea and then studied with dodecyl sulphate or urea polyacrylamide gel electrophoresis showed a single 43‐kDa band. L. casei ATPase subunits could not be separated by isoelectrofocusing in 8 M urea/polyacrylamide gel (a pH gradient of 0.2–0.3 cm was used) and migrated as a single band of isoelectric point at pH 4.2.An electron microscopic study of the purified L. casei ATPase negatively stained with uranyl acetate showed particles of very regular structure. The predominant type of image was found to be a hexagonal particle 9.0–10.0 nm in size with 6 n point symmetry. An analysis of five different projections indicated that six similar subunits are arranged in two layers (three subunits in each layer) at vertices of two triangles rotated at 180°. This structure has a 32 point group symmetry.It is concluded that the detachable part of membrane N,N×‐dicyclohexylcarbodiimide‐sensitive ATPase of L. casei is composed of six similar subunits. Such a simplified version of factor F1 may be regarded as an evolutionary precursor of the catalytic part of the H+ ‐ATP synthase of aerobic and photosynthetic bacteria, mitochondria, and chloroplasts, containing two types of major and 2–3 types of minor subunits. The possibility is discussed that simplicity of L. casei ATPase is due to the fact that in the cell it operates as an ATP‐splitting, rather than a synthesizing, mechanism.

Purification and characterization of prorenin from porcine kidney.

Prorenin was purified extensively from porcine kidney by a procedure involving extraction at pH 6.5 in the presence of protease inhibitors, ammonium sulfate fractionation, affinity chromatography on pepstatin-aminohexyl-Sepharose, acetone fractionation, chromatography on DEAE-cellulose, gel filtration on Ultrogel AcA 44, chromatography on concanavalin A-Sepharose, and chromatography on CM-Sepharose. The resulting preparation was essentially homogeneous as judged by sodium dodecyl sulfate (SDS) polyacrylamide-gel electrophoresis. The molecular weight of the preparation was estimated to be 39,000 by SDS-gel electrophoresis and 44,000 by gel filtration on Ultrogel AcA 44, and the isoelectric point was at pH 5.1. The purified prorenin was stable for 60 min at 37 degrees C between pH 3.0 and 9.0 and on storage for 4 weeks at--80 degrees C. The prorenin did not show any renin activity which appeared after trypsinization. The molecular weight of trypsin-activated prorenin was estimated to be 40,000 by gel filtration on Ultrogel AcA 44. The specific renin activity was 2.06 mg angiotensin I/mg of prorenin per h, and the optimal pH for the renin activity was in the pH region from 6.0 to 6.5 with hog and rat plasma angiotensinogens as the substrates. Two distinct isoelectric points were identified at pH 4.9 and pH 5.0 with the trypsin-activated prorenin.

A Novel Peptidoglycan-Associated Lipoprotein (PAL) Found in the Outer Membrane of <italic>Proteus mirabilis</italic> and Other Gram-Negative Bacteria

A novel peptidoglycan-associated lipoprotein (PAL) was found in the cell envelope of Proteus mirabilis. This protein showed the following properties: (1) The apparent molecular weight in sodium dodecyl sulfate (SDS) polyacrylamide gel was 18,000. (2) The protein was present in the cell envelope in a form very closely, but not covalently, associated with the peptidoglycan layer. (3) The protein was recovered predominantly from the outer membrane fraction after separation of the cell envelopes. (4) [1-14C]Palmitic acid and [2-3H]glycerol were incorporated into the protein. (5) The protein contained covalently linked fatty acids (about 3 mol of fatty acid per mol of protein). (6) An unidentified compound was present in the hydrolysate of the protein. These properties, except for molecular weight and non-covalent association with the peptidoglycan, showed resemblance to those of Braun's lipoprotein. However the protein was distinct from Braun's lipoprotein in regard to amino acid composition. A similar peptidoglycan-associated lipoprotein (PAL) was present widely in the cell envelopes of various Gram-negative bacteria. P. mirabilis contains about twelve times as much PAL as Escherichia coli. Antiserum against PAL of P. mirabilis was cross-reactive against PAL of E. coli, but not against Braun's lipoprotein of E. coli.

The extraction from maize (Zea mays) root cells of membrane-bound protein with Ca2+-dependent ATPase activity and its possible role in membrane fusion in vitro.

Membrane fusion in vitro between Golgi apparatus- and plasma-membrane-rich fractions isolated from maize (Zea mays) roots was found to be dependent on Ca2+ and the membrane proteins. Trypsin treatment of mixed membrane fractions before the addition of Ca2+ inhibited their ability to fuse. It resulted also in a selective and progressive elimination of a characteristic intense polypeptide band (B1) on gel electrophoresis. This polypeptide was not removed by chymotrypsin or thermolysin. B1 is an integral membrane protein with an exposed portion to the outside. Sodium deoxycholate was used to solubilize the proteins of mixed membrane fractions. Extracted proteins analysed by non-SDS (sodium dodecyl sulphate) polyacrylamide-gel electrophoresis revealed the presence of four isolated bands. When re-electrophoresed in the presence of SDS, one of these bands exhibited the same mobility as polypeptide B1. Enzymic staining of non-SDS-polyacrylamide gels showed that this protein has Ca2+- and Mg2+-dependent ATPase activity. Its possible role in membrane fusion is discussed.

Developmental Changes in Polypeptide Composition of, and Precursor Incorporation into, Cellular and Subcellular Fractions of Rat Cerebral Cortex

Neuronal-enriched and glial-enriched fractions from rat cerebral cortex at 2, 5, 9, 14 and 23 days postnatally, and subcellular fractions from 2, 14 and 46 day old rat were prepared. The polypeptide composition of all fractions was analysed by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis and quantified by densitometry. Fifty-nine polypeptides (mol. wts., 13,200-251,000) were resolved in the cell fractions of which the majority remained unchanged throughout postnatal development. Three polypeptides (mol. wts., 102,000, 56,000, 53,700) were found to increase in amount developmentally in both cellular fractions, the latter two showing a peak in relative amount on day 14 and a subsequent decline. Three polypeptides (mol. wts., 47,000, 28,200, 17,400) were found to be common to the glial-enriched fraction as well as the myelin fraction, and all showed a developmental increase. The neuronal-enriched fraction was found to be enriched in five polypeptides of which one (mol. wt., 51,900) showed a developmental increase after ten days postnatally, the others (mol. wts., 178,700, 142,000, 109,000, 24,000) showing a decrease. In vitro incorporation of [35S]-methionine into the glial-enriched fraction was carried out, and a developmental decline was observed in the labelling of a polypeptide of 42,000 mol. wt.

Identification of different forms of the murein-bound lipoprotein found in isolated outer membranes of Escherichia coli.

The identification of the free and murein-bound forms of the Escherichia coli lipoprotein on dodecylsulphate-polyacrylamide gels was systematically investigated by analyzing the low-molecular-weight proteins (Mr less than 20 000) of both cytoplasmic and outer membranes. The free form of the lipoprotein was identified on 15% polyacrylamide gels as the fastest migrating component (Mr = 7200-7500) of isolated outer membranes; it could be separated from a small cytoplasmic membrane protein (Mr = 6500) which was probably identical to the dicyclohexylcarbodiimide binding proteolipid of the membrane-bound ATPase. Lysozyme treatment of both outer membranes and murein sacculi failed to convert the murein-bound lipoprotein into a fragment of uniform size; instead the bound form appeared as a series of bands consisting of lipoprotein bound to one, two,...eight murein subunits. The composition of this ladder depended on the method used to isolate outer membranes. Beside these lipoprotein bands the outer membrane contained two other proteins, III and V; the relation of these proteins to previously described proteins is discussed.

Filamentous Protein of Basal Cell Epithelioma: Characteristics In Vivo and In Vitro<xref ref-type="fn" rid="FN2">2</xref><xref ref-type="fn" rid="FN3">3</xref>

The sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) pattern of the citrate-soluble fibrous protein isolated from human basal cell epitheliomas showed polypeptides with molecular weights of 43,000, 45,000, and 59,000. These polypeptides, found in the protein of normal epidermis, were present in a different proportion in this tumor tissue. Basal cell epitheliomas were cultured by the use of killed murine 3T3 feeder layers but only when 10(-9) M cholera toxin was present. The SDS-PAGE pattern of fibrous protein from cultured tumor cells was identical to the pattern of cultured normal human epidermal cells, and cornified cell envelopes were found in both types of cultures. Electron microscopy showed stratified cells that contained desmosomes, tonofilaments, and keratohyalin granules.

Near-infrared absorption spectra of light harvesting bacteriochlorophyll protein complexes from Chromatium vinosum.

Light harvesting (LH) bacteriochlorophyll (Bchl) protein complexes were isolated from chromatophores of Chromatium vinosum, by the combination of detergent solubilization, sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis (PAGE) and hydroxyapatite chromatography. Addition of the absorption spectra of these complexes reproduced the absorption spectrum of chromatophores from which these complexes were derived. This result led to the conclusion that these isolated complexes retained the near-infrared absorption spectra which these complexes showed as they existed in chromatophores. Two kinds of spectrally different chromatophores were obtained under different culture conditions. One of them contained two kinds of LH Bchl protein complexes; B890 containing and B850-B800 containing complexes, and the other contained, in addition, B820-B800 containing complex. B890 containing complexes from the two types of chromatophores were spectrally similar, whereas B850-B800 containing complexes were not the same with respect to the location of absorption maxima and the content of B850. It was shown that the variation of the near-infrared absorption spectra of the chromatophores is due to not only the variation of the ratio of complexes but also the variation of the absorption spectrum of a particular complex.