Abstract：
:The PEGylated hemoglobin (Hb) has been evaluated as a potential blood substitute. In an attempt to understand the autoxidation of the PEGylated Hb, we have studied the autoxidation of the PEGylated Hb site-specifically modified at Cys-93(beta) or at Val-1(beta). PEGylation of Hb at Cys-93(beta) perturbed the heme environment and increased the autoxidation rate of Hb, which is at a higher level than that caused by PEGylation at Val-1(beta). The perturbation of the heme environment of Hb is attributed to the maleimide modification at Cys-93(beta) and not due to conjugation of the PEG chains. However, the PEG chains enhance the autoxidation and the H 2O 2 mediated oxidation of Hb. Accordingly, the PEG chains are assumed to increase the water molecules in the hydration layer of Hb and enhance the autoxidation by promoting the nucleophilic attack of heme. The autoxidation rate of the PEGylated Hb does not show an inverse correlation with the oxygen affinity. The H 2O 2 mediated structural loss and the heme loss of Hb are increased by maleimide modification at Cys-93(beta) and further decreased by conjugation of the PEG chains. The autoxidation of the PEGylated Hbs is attenuated significantly in the plasma, possibly due to the presence of the antioxidant species in the plasma. This result is consistent with the recent suggestion that there is no direct correlation between the in vitro and in vivo autoxidation of the PEGylated Hb. Therefore, the pattern of PEGylation can be manipulated for the design of the PEGylated Hb with minimal autoxidation.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Hu T,Li D,Manjula BN,Acharya SAdoi
10.1021/bi800906zsubject
Has Abstractpub_date
2008-10-14 00:00:00pages
10981-90issue
41eissn
0006-2960issn
1520-4995journal_volume
47pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:The soluble domains of the b and b' subunits of the ATP synthase of the cyanobacterium Synechocystis PCC 6803 were expressed with His tags attached to their N-termini. Following purification, the polypeptides were characterized by chemical cross-linking, analytical ultracentrifugation, and circular dichroism spectrosc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi001821j
更新日期：2001-01-09 00:00:00
abstract：:The reactivity of a series of para-substituted phenolic compounds in the peroxidation catalyzed by chloroperoxidase was investigated, and the results were interpreted on the basis of the binding characteristics of the substrates to the active site of the enzyme. Marked selectivity effects are observed. These operate t...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00187a001
更新日期：1994-05-31 00:00:00
abstract：:The ability of cell-penetrating peptides (CPPs) to cross cell membranes has found numerous applications in the delivery of bioactive compounds to the cytosol of living cells. Their internalization mechanisms have been questioned many times, and after 20 years of intense debate, it is now widely accepted that both ener...
journal_title：Biochemistry
pub_type： 杂志文章,评审
doi：10.1021/bi501392n
更新日期：2015-01-20 00:00:00
abstract：:The BCL-2 gene encodes a 25 kDa membrane protein that plays critical roles in the control of apoptosis. The regulation of BCL-2 gene expression is highly complex and occurs both transcriptionally and posttranscriptionally. In particular, the 5' upstream region of BCL-2 contains a number of elements that control its ex...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi100957h
更新日期：2010-09-28 00:00:00
abstract：:The catalysis of the chemical exchange between acetaldehyde and its hydrate by bovine carbonic anhydrase B was investigated by the NMR line broadening and saturation transfer techniques. While both chemical exchange and binding to the enzyme had an effect on the line broadening of acetaldehyde and its hydrate, the sat...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00550a021
更新日期：1980-04-29 00:00:00
abstract：:Heme oxygenases convert heme to free iron, CO, and biliverdin. Saccharomyces cerevisiae and Candida albicans express putative heme oxygenases that are required for the acquisition of iron from heme, a critical process for fungal survival and virulence. The putative heme oxygenases Hmx1 and CaHmx1 from S. cerevisiae an...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi061429r
更新日期：2006-12-12 00:00:00
abstract：:Annexin A2 is a member of the annexin family of Ca(2+)-dependent lipid binding proteins and believed to be engaged in membrane transport processes in a number of cell types. In small intestinal enterocytes, we localized annexin A2 to the brush border region, where it was found mainly on the lumenal side of the microvi...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0355239
更新日期：2003-12-16 00:00:00
abstract：:Aerobic and facultative bacteria and archaea harboring mer loci exhibit resistance to the toxic effects of Hg(II) and organomercurials [RHg(I)]. In broad spectrum resistance, RHg(I) is converted to less toxic Hg(0) in the cytosol by the sequential action of organomercurial lyase (MerB: RHg(I) → RH + Hg(II)) and mercur...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi100802k
更新日期：2010-09-21 00:00:00
abstract：:The key polyamine catabolizing enzyme spermidine-spermine N1-acetyltransferase (SSAT) is among the few genes known to be inducible by the natural polyamines. Certain polyamine analogs markedly exaggerate this response and thus provide useful tools for studying the underlying regulatory mechanisms. As shown here, the a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9612273
更新日期：1996-11-12 00:00:00
abstract：:The high molecular weight folate binding protein of rat liver cytosol has been purified to apparent homogeneity. Purification was achieved by using a combination of gel filtration, O-(diethylaminoethyl)cellulose chromatography, and affinity chromatography. This folate binding protein was initially identified during pu...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00261a036
更新日期：1982-08-31 00:00:00
abstract：:The envelope glycoprotein of HIV-1 consists of the surface subunit gp120 and the transmembrane subunit gp41. Binding of gp120 to target cell receptors induces a conformational change in gp41, which then mediates the fusion of viral and cellular membranes. A buried isoleucine (Ile573) in a central trimeric coiled coil ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0024759
更新日期：2001-03-06 00:00:00
abstract：:Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme that also functions in transcriptional regulation, oxidative stress, vesicular trafficking, and apoptosis. Because GAPDH is required for the insertion of cellular heme into inducible nitric oxide synthase [Chakravarti, R., et al. (2010) Proc. Natl...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi300863a
更新日期：2012-10-30 00:00:00
abstract：:The structures of synthetic peptides corresponding to regions of putative secondary structure in the cellular prion protein PrPC were studied as models for the conformational transition that features in the formation of the pathogenic isoform, PrPSc. Transgenetic studies argue that these PrP isoforms interact during t...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00013a006
更新日期：1995-04-04 00:00:00
abstract：:Steady-state and femtosecond time-resolved optical methods have been used to compare the spectroscopic features and energy transfer dynamics of two systematically different light-harvesting complexes from the dinoflagellate Amphidinium carterae: main-form (MFPCP) and high-salt (HSPCP) peridinin-chlorophyll a-proteins....
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi061217u
更新日期：2006-11-28 00:00:00
abstract：:Differential expression of subunit genes from the nicotinic acetylcholine receptor (AChR) superfamily yields distinct receptor subtypes. As each AChR subtype has a specific subunit composition and many subunit combinations appear not to be expressed, each subunit must contain some information leading to proper assembl...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00254a031
更新日期：1994-12-20 00:00:00
abstract：:We report here that the DNA strand scission by dynemicin A is not only sequence-specific but also conformation-specific. The salt-induced B----Z conformational transition dramatically enhanced the cleavage by dynemicin A in a B-Z junction region. By contrast, the bleomycin-Fe(II) complex, the elsamicin A-Fe(II) comple...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00144a019
更新日期：1992-07-28 00:00:00
abstract：:Most proteins are denatured by heat treatment, and the process is usually irreversible. However, some proteins, such as hyperthermophilic proteins are known to be stable even at the boiling temperature of water. We here describe a systematic investigation of thermal behavior of proteins by purifying and characterizing...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi001441y
更新日期：2000-12-05 00:00:00
abstract：:The relationship between GTP hydrolysis and microtubule assembly has been investigated by using a rapid filtration method. Microtubules assembled from phosphocellulose-purified tubulin, double-labeled with [gamma-32P]- and [3H]GTP, were trapped and washed free of unbound nucleotide on glass fiber filters. The transien...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00479a022
更新日期：1990-07-10 00:00:00
abstract：:An overexpression system for spinach apocytochrome b(6) as a fusion protein to a maltose-binding protein in Escherichia coli was established using the expression vector pMalp2. The fusion of the cytochrome b(6) to the periplasmic maltose-binding protein directs the cytochrome on the Sec-dependent pathway. The cytochro...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi047422w
更新日期：2005-05-24 00:00:00
abstract：:Factors determining conformations of imidazole axially coordinated to heme in heme proteins were investigated by analyzing 693 hemes in 432 different crystal structures of heme proteins from the Protein Data Bank (PDB), where at least one histidine is ligated to heme. The results from a search of the PDB for protein s...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi010428q
更新日期：2001-07-03 00:00:00
abstract：:The human LD78 protein (sometimes referred to as human macrophage inflammatory protein-1 alpha) has been shown to protect multipotential hemopoietic stem cells from the effects of cytotoxic agents. Administration of the recombinant stem cell inhibitor molecule LD78 as an adjunct to chemotherapy has potential clinical ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00071a024
更新日期：1993-05-25 00:00:00
abstract：:The stereochemical course of the phospho group transfer catalyzed by mutant (S102C) alkaline phosphatase from Escherichia coli was investigated by using 31P nuclear magnetic resonance spectroscopy. Transphosphorylation from 4-nitrophenyl (Rp)-[16O, 17O, 18O]phosphate to (S)-propane-1,2-diol occurs with overall retenti...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00413a029
更新日期：1988-06-28 00:00:00
abstract：:The fibronectin receptor (FnR), the vitronectin receptor (VnR), and the platelet membrane glycoprotein (GP) IIb-IIIa complex are members of a family of cell adhesion receptors, which consist of noncovalently associated alpha- and beta-subunits. The present study was designed to compare the cDNA-derived protein sequenc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00399a021
更新日期：1987-12-15 00:00:00
abstract：:We have measured the base-pair lifetimes in oligodeoxynucleotides containing tracts of A.T base pairs using imino proton magnetic resonance. When the tract contains more than four consecutive A.T base pairs, possibly including a 5'-AT step but not a 5'-TA step, anomalously long lifetimes are observed. For example, the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00425a004
更新日期：1988-12-13 00:00:00
abstract：:Synthetic O-glycopeptides containing one or two GalNAc residues attached to Ser or Thr were used as substrates to investigate the effect of peptide structure on the activity of crude preparations of UDP-Gal:GalNAc alpha-R beta 3-Gal-transferase from pig stomach and pig and rat colonic mucosa and of a partially purifie...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00496a008
更新日期：1990-11-06 00:00:00
abstract：:Escherichia coli helicase II (UvrD) protein can initiate unwinding of duplex DNA at blunt ends or nicks, although these reactions require excess protein. We have undertaken kinetic studies of these reactions in order to probe the mechanism of initiation of unwinding. DNA unwinding was monitored directly by using agaro...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00066a039
更新日期：1993-04-20 00:00:00
abstract：:Centrioles are essential components of the animal centrosome and play crucial roles in the formation of cilia and flagella. They are cylindrical structures composed of nine triplet microtubules organized around a central cartwheel. Recent studies have identified spindle assembly abnormal protein SAS-6 as a critical co...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.5b00978
更新日期：2015-10-20 00:00:00
abstract：:We have studied the effect of the binding of ribosomal protein S1 and initiation factor IF3 on the accessibility of nucleotide residues 584-1506 in the small subunit of the Escherichia coli ribosome. Protein S1 strongly decreases RNase V1 attack at G1164, in hairpin 40 of the 3' major domain, and weakly decreases DMS ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00112a007
更新日期：1991-12-03 00:00:00
abstract：:The doublet at 850 and 830 cm-1 in the Raman spectra of proteins containing tyrosyl residues has been examined as to its origin and the relation of its components to the environment of the phenyl ring, the state of the phenolic hydroxyl group, and the conformation of the amino acid backbone. Raman spectral studies on ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00693a014
更新日期：1975-11-04 00:00:00
abstract：:Brief exposure of purple membrane (PM) to dilute Triton X-100 eliminates the actinic light effect on the relative amounts of fast M (Mf) and slow M (Ms) intermediates and alters the character and kinetics of the photocycle, without destroying the native BR trimers (Mukhopadhyay et al., 1994). Particular membrane lipid...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi960738m
更新日期：1996-07-16 00:00:00
