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101.
Paliakkara L. Jaison Vadakkedath M. Kannan Mandagini Geetha Padinjaradath S. Appukuttan 《Journal of biosciences》1993,18(2):187-193
Naturally occurring serum IgG against terminal α-galactoside epitopes (anti-Gal), present exclusively in man, apes and old
world monkeys, was used as probe for these epitopes in human brain. Human brain grey matter soluble glycoproteins enriched
inα galactosyl groups by affinity chromatography on jacalin-sepharose, specifically binds to human anti-Gal in immuno dot
blots. Anti-Gal recognized exclusively the terminal α galactoside epitope in human brain glycoproteins since binding was abolished
by the presence of 1-0-methyl α-D-galactopyranoside as well as by pretreatment of glycoproteins with coffee bean α-galactosidase.
Anti-Gal-peroxidase staining of jacalin-binding human brain glycoproteins in western immuno blots revealed mainly five anti-Gal-binding
polypeptides withM
r
(in kDa) of 94, 108, 180, 210 and 230 respectively. Since the presence of anti-Gal in higher animals accompanies suppression
of the corresponding epitope in most tissues, apparently to maintain immunological balance, possible implications of the above
observation for autoimmunity, tumor metastasis and infection are discussed. 相似文献
102.
Zac Yates Kannan Gunasekaran Hongxing Zhou Zhonghua Hu Zhi Liu Randal R. Ketchem Boxu Yan 《The Journal of biological chemistry》2010,285(24):18662-18671
Hydroxyl radicals induce hinge cleavage in a human IgG1 molecule via initial radical formation at the first hinge Cys231 followed by electron transfer to the upper hinge residues. To enable engineering of a stable monoclonal antibody hinge, we investigated the role of the hinge His229 residue using structure modeling and site-directed mutagenesis. Direct involvement of His229 in the reaction mechanism is suggested by a 75–85% reduction of the hinge cleavage for variants in which His229 was substituted with either Gln, Ser, or Ala. In contrast, mutation of Lys227 to Gln, Ser, or Ala increased hinge cleavage. However, the H229S/K227S double mutant shows hinge cleavage levels similar to that of the single H229S variant, further revealing the importance of His229. Examination of the hinge structure shows that His229 is capable of forming hydrogen bonds with surrounding residues. These observations led us to hypothesize that the imidazole ring of His229 may function to facilitate the cleavage by forming a transient radical center that is capable of extracting a proton from neighboring residues. The work presented here suggests the feasibility of engineering a new generation of monoclonal antibodies capable of resisting hinge cleavage to improve product stability and efficacy. 相似文献
103.
Nayoung Kang Ah Hyun Jun Yangzom Doma Bhutia Natarajan Kannan Jashvant D. Unadkat Rajgopal Govindarajan 《The Journal of biological chemistry》2010,285(36):28343-28352
Accumulating evidence reveals that sole mutations in hENT3 cause a spectrum of human genetic disorders. Among these include H syndrome, characterized by scleroderma, hyperpigmentation, hypertrichosis, hepatomegaly, cardiac abnormalities and musculoskeletal deformities, pigmented hypertrichotic dermatosis with insulin-dependent diabetes syndrome, characterized by autoantibody-negative diabetes mellitus and skin deformities, familial Rosai-Dorfman disease, characterized by short stature, familial histiocytosis and sinus histiocytosis with massive lymphadenopathy (SHML), characterized by severe tissue infiltration of immune cells and swollen lymph nodes. hENT3 spectrum disorders share a common mutation and share overlapping clinical manifestations that display many intriguing resemblances to mitochondrial and lysosomal disorders. Although earlier studies identify hENT3 as a mitochondrial and a lysosomal nucleoside transporter, the precise connections between hENT3 and the pathophysiology of these disorders remain unresolved. In this study, we performed functional and biochemical characterization of these mutations in hENT3. We report severe reductions/losses of hENT3 nucleoside transport functions of hENT3 syndrome mutants. In addition to transport alterations, we provide evidence for possible loss of hENT3 functions in all H and pigmented hypertrichotic dermatosis with insulin-dependent diabetes syndromes due to either mistrafficking or altered stability of mutant hENT3 proteins. 相似文献
104.
105.
Carlson Courtney Singh Nitin K. Bibra Mohit Sani Rajesh K. Venkateswaran Kasthuri 《Applied microbiology and biotechnology》2018,102(4):1869-1887
Applied Microbiology and Biotechnology - We have characterized a broad collection of extremophilic bacterial isolates from a deep subsurface mine, compost dumping sites, and several hot spring... 相似文献
106.
Olivia L. McGovern Yolanda Rivera‐Cuevas Geetha Kannan Andrew J. Narwold Jr Vern B. Carruthers 《Traffic (Copenhagen, Denmark)》2018,19(5):336-353
Host cytosolic proteins are endocytosed by Toxoplasma gondii and degraded in its lysosome‐like compartment, the vacuolar compartment (VAC), but the dynamics and route of endocytic trafficking remain undefined. Conserved endocytic components and plant‐like features suggest T. gondii endocytic trafficking involves transit through early and late endosome‐like compartments (ELCs) and potentially the trans‐Golgi network (TGN) as in plants. However, exocytic trafficking to regulated secretory organelles, micronemes and rhoptries, also proceeds through ELCs and requires classical endocytic components, including a dynamin‐related protein, DrpB. Here, we show that host cytosolic proteins are endocytosed within 7 minutes post‐invasion, trafficked through ELCs en route to the VAC, and degraded within 30 minutes. We could not definitively interpret if ingested protein is trafficked through the TGN. We also found that parasites ingest material from the host cytosol throughout the parasite cell cycle. Ingested host proteins colocalize with immature microneme proteins, proM2AP and proMIC5, in transit to the micronemes, but not with the immature rhoptry protein proRON4, indicating that endocytic trafficking of ingested protein intersects with exocytic trafficking of microneme proteins. Finally, we show that conditional expression of a DrpB dominant negative mutant increases T. gondii ingestion of host‐derived proteins, suggesting that DrpB is not required for parasite endocytosis. 相似文献
107.
Effects of growth substances on the absorption and transport of iron plants 总被引:2,自引:2,他引:0
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The effects of a number of growth substances on the absorption and translocation of iron were studied in bean plants. Gibberellic acid application to the trifoliate leaf enhanced absorption of Fe applied to the primary leaf. 2-Chloroethyltrimethylammonium chloride increased absorption by the primary leaf while 6-furfurylaminopurine (kinetin) increased the transport of Fe from the primary leaf to other parts. When the roots were pretreated with gibberellic acid, the absorption of Fe by the primary leaf and subsequent transport to the trifoliate leaves were increased. Triiodobenzoic acid reduced the absorption and transport of Fe. 相似文献
108.
Muthu Manikandan Judy Gopal Rangarajulu Senthil Kumaran Vijayaraghavan Kannan Sechul Chun 《Preparative biochemistry & biotechnology》2016,46(2):192-199
Phytoremediation using timber-yielding tree species is considered to be the most efficient method for chromium/tannery effluent-contaminated sites. In this study, we have chosen Albizzia lebbeck, a chromium hyperaccumulator plant, and studied one of its chromium detoxification processes operated by its endophytic bacterial assemblage. Out of the four different groups of endophytic bacteria comprising Pseudomonas, Rhizobium, Bacillus, and Salinicoccus identified from A. lebbeck employed in phytoremediation of tannery effluent-contaminated soil, Bacillus predominated with three species, which exhibited not only remarkable chromium accumulation ability but also high chromium reductase activity. A chromate reductase was purified to homogeneity from the most efficient chromium accumulator, Bacillus sp. DGV 019, and the purified 34.2-kD enzyme was observed to be stable at temperatures from 20°C to 60°C. The enzyme was active over a wide range of pH values (4.0–9.0). Furthermore, the enzyme activity was enhanced with the electron donors NADH, followed by NADPH, not affected by glutathione and ascorbic acid. Cu2+ enhanced the activity of the purified enzyme but was inhibited by Zn2+ and etheylenediamine tetraacetic acid (EDTA). In conclusion, due to its versatile adaptability the chromate reductase can be used for chromium remediation. 相似文献
109.
Complex‐I Alteration and Enhanced Mitochondrial Fusion Are Associated With Prostate Cancer Progression
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110.