Immunological similarity between

In order to investigate the active sites of these proteins, laccases I and III were subjected to ESR (electron spin resonance) spectroscopic analysis. The ESR spectra shown in Figure 5 indicate clear differences in peaks 2 and 6 which support the concept that the copper atoms in laccases I and III have different conformations in each molecule. Furthermore, immunological similarity between laccases I and III was also investigated. Antibody specific for laccase III was prepared from rabbit serum by conventional methods. When applied to Ouchterlony diffusion plates containing laccase I, no precipitation lines developed (Figure 6). This result showed that there were no conserved epitopes on the surfaces laccases I and III. 

With the divergence of two species from a common ancestor, mutations in the structural genes encoding similar proteins result in amino acid differences between the proteins produced by the now separate species. The degree of immunological similarity between any two such proteins is directly related to the evolutionary distance between the two species. Different proteins evolve at different rates. The structural basis for this difference in rate is that, for slowly evolving proteins, changes in amino acid sequence... 

CHY-1 is also described as anionic and CHY-2 as cationic because of their differing electrophoretic mobility the cationic form predominates. The molecular weight of both forms is approximately 25,000. There is close immunological similarity between the chymotrypsins and chymotrypsino-gens. CHY, like TRY, is bound in plasma by ai-antitrypsin and a2-macroglobulin. 

Otton, S.V. Tyndale, R.F. Wu, D. Inaba, T. Kalow, W. and Sellers, E.M. Catalytic and immunologic similarities between monkey and human liver c54ochrome P-450dbl (human cytochrome P450 2D6). DrugMetab Dispos 20(1) 1-5, 1992. 

A minor isoenzyme of human prostatic acid phosphatase (pi 5.5) has been separated from the major isoenzyme (pi 4.9). Immunological similarities between the two enzymes were demonstrated. 

To elucidate some enzymatic characteristics of the isolated laccases I, II, and III, substrate specificities for several simple phenols, electrophoresis patterns, ultraviolet spectra, electron spin resonance spectra, copper content, and immunological similarities were investigated. Tyrosine, tannic acid, g c acid, hydroquinone, catechol, pyrogallol, p-cresol, homocatechol, a-naphthol, -naphthol, p-phenylenediamine, and p-benzoquinone as substrates. No differences in the specificities of these substrates was found. The UV spectra for the laccases under stucfy are shown in Figure 4. Laccase III displays three adsorption bands (280, 405, and 600nm), laccase II shows one band 280nm), and laccase I shows two bands (280 and 405 nm). These data appear to indicate differences in chemical structure. The results of the copper content analysis (10) and two-dimensional electrophoresis also indicate that these fractions are completely different proteins (10), Therefore, we may expect differences in substrate specificities between the three laccase fractions for more lignin-like substrates, yet no difference for some simple phenolic substrates. 

Lyophilized factor VIII has been used as substitution therapy in patients with hemophilia A. Most, but not all, recombinant factor VIII (recFVIII) is structurally and immunologically similar to plasma-derived factor VIII, and it has been well tolerated by patients in clinical trials. A major concern about recombinant factor VIII has been the occurrence inhibitors (1). However, there is evidence that there is no difference in the occurrence of inhibitors between recombinant factor VIII and plasma-derived factor VIII (2). 

The peptide moiety of wax D fractions of human strains seems to be necessary for the activity of these fractions as immunological adjuvants (see p. 235) this may be due to the close chemical similarity between the structure of the water-soluble portion of wax D and the cell wall of Mycobacteria, since the latter contains the same three amino acids (alanine, glutamic acid, and a, c-diaminopimelic acid) and the same sugars (arabinose, mannose, galactose, and aminohexoses). Wax D of human strains might be considered to be a monomer of the cell wall, heavily esterified with mycolic acid. 

Vertebrate-like neuropeptides are present in insects as demonstrated immunologically, and probably vice versa, but it is unclear what the function is for these peptides in their heterologous animal system. The structural similarities between these molecules suggest that common, biologically-active ancestral molecules may have existed and evolved to perform different functions depending on the physiological diversity and needs of the animals involved. 

Polyclonal rabbit antibodies against V 2 and V 3 exhibit a positive cross reaction with E. coli DNA polymerase I in an ELISA test. The immunological affinity between V 3 and polymerase is very high. Structurally as well, the two enzymes are quite similar They comprise a monomer and have a plurality of active centers or activities as component of a single polypeptide. 

Trichome PPO appears to be an example of an evolutionary modification of an existing plant enzyme for use as an insect defense mechanism. PPO enzymes, of molecular weight 45,000, are localized in the thylakoid and are nearly ubiquitous in tissues of plants (12,18.). Unlike other known nuclear encoded chloroplast proteins, the 45 kD thylakoid PPO, whose function is unknown, is translated at its mature size of 45 kD, and does not possess a transit peptide sequence (19). In contrast, the 5 9 kD trichome PPO is translated as a 67 kD precursor and localized in the leucoplasts of trichome and outer epidermal cells. Immunological and primary sequence similarities between the 59 kD trichome PPO and the 45 kD thylakoid PPO underscore the close evolutionary relationship between these two proteins. The apparent advantage of the very high concentration of PPO in the trichome is the high initial rate of catalysis which results upon trichome rupture, facilitating the entrapment of mobile insects. 

Halmepuro L, Lowenstein H (1985) Immunological investigation of possible structural similarities between pollen antigens and antigens in apple, carrot and celery tuber. Allergy 40 264-272... 

Both crystallographic studies of nitrite binding to the oxidized enzyme (12) and studies of Type 2 Cu-depleted enzyme (24), where a linear correlation between Type 2 Cu content and specific activity was observed, have shown that the Type 2 Cu center is the site at which NO2 binds and is reduced, analogous to the heme center in the heme cdi enzymes. The role of the Type 1 Cu appears to be that of an electron transfer center, analogous to the role of the heme c in the heme cd enzymes. Although a wide variety of copper contents, colors, and quaternary structures has been reported for Cu NiR s, it seems likely that most, if not all, of the enzymes have structures and optimal copper contents similar to that of the A. cycloclastes enzymes. This assertion is based on (i) extensive sequence similarities between the A. cycloclastes NiR and that from R aureofaciens, previously reported to contain only a single Type 1 Cu per monomer (11) (ii) on studies of the Cu content of the A. xylosoxidans NiR, also previously reported to contain only Type 1 Cu (1) and (iii) on the extensive immunological cross-reactivity observed with antibodies to the A. cycloclastes enzyme (7). 

Immunological similarities observed between CB and ammodytoxin were used to investigate the toxic site of crotoxin. In the case of ammodytoxin A, the search of a toxic site has taken advantage of the existence of two other isoenzymes, ammodytoxin B and C, which are 28 and 17 times less toxic (Ritonja et al, 1986 Krizaj et al, 1989). Ammodytoxin A, B and C, which are all composed of 122 amino acids, differ only in their C-terminal parts. Polyclonal antibodies prepared against three peptides covering the C-terminal part revealed that a stretch of amino acids (106-113) could be involved in the interaction of ammodytoxin A with its acceptor (Curin-Serbec etal, 99 ). The interaction of these antipeptide antibodies with CB and crotoxin, as well as their ability to reduce the lethal potency but not the... 

Though benzoylformate decarboxylase was found to have significant sequence similarities with pjnuvate decarboxylj e [87], in immunological comparisons between these enzymes no common epitopes were detected by antibodies raised against each of them [82]. 

---