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71.
A novel glycosyl-amino acid linkage: rabbit-muscle glycogen is covalently linked to a protein via tyrosine 总被引:6,自引:0,他引:6
A recent review summarizes our identification in rabbit-muscle glycogen of a protein that resists all attempts at removal by means that should displace non-covalently bound protein [Kennedy et al. (1985) In Membranes and Muscle (Berman, M.C., Gevers, W. and Opie, L.H. eds.) pp. 65-84, ICSU Press/IRL Press, Oxford]. Here we confirm that the glycogen is covalently bonded to the protein and report that the attachment is via a novel glycosidic linkage involving the hydroxyl group of tyrosine. 相似文献
72.
Fatty acyl-AMP as an intermediate in fatty acid reduction to aldehyde in luminescent bacteria 总被引:4,自引:0,他引:4
The acyl protein synthetase component (50K) of the fatty acid reductase complex from the luminescent system of Photobacterium phosphoreum has been found to catalyze the activation of fatty acid via formation of an enzyme bound acyl-AMP (carboxyphosphate mixed anhydride) immediately prior to the acylation of the enzyme. PPi-ATP exchange and nucleotide binding experiments are dependent on fatty acid and indicate that the fatty acyl-AMP is directly formed and that an adenylated enzyme intermediate is not part of the mechanism. The formation of acyl-AMP from fatty acid and ATP is reversible with a standard free energy of -2 kcal/mol, and is dependent on Mg2+. The fatty acyl-AMP intermediate has been isolated and shown to be part of the pathway of fatty acid reduction. The 34K component of the complex, which strongly stimulates the acylation of the 50K protein by fatty acyl-AMP or fatty acid and ATP, is not required for the formation of acyl-AMP showing that it differentially affects the fatty acid activation and acylation steps catalyzed by the 50K protein. 相似文献
73.
Whole homogenates of bulb mites rapidly metabolized 2-phenylethylamine (PEA) but were appreciably less active against tryptamine, 5-hydroxytryptamine, and dopamine; no degradation of octopamine was detected. The rate of PEA degradation by bulb mites was dependent upon both substrate and homogenate concentrations. PEA degradation was inhibited by pargyline (pI50, 6.7), tranylcypromine (pI50 6.2), and harmaline (pI50 4.1), but not by 5-chloro-2,4-dimethoxyformanilide. These results suggested that PEA metabolism by bulb mite homogenates was catalyzed mainly by Type B monoamine oxidase.Contribution from the Missouri Agricultural Experiment Station, Columbia, MO. Journal Series No. 9777 相似文献
74.
R C Leif S Schwartz C M Rodriguez L Pell-Fernandez M Groves S B Leif M Cayer H Crews 《Cytometry》1985,6(1):13-21
Combined DC (Coulter Volume) and radio frequency impedance studies were performed on human erythrocytes which had been separated by buoyant density in linear, neutral, isotonic bovine serum albumin gradients. The individual buoyant density fractions showed no reproducible shift in volume with buoyant density but did show a shift with opacity, radio frequency impedance divided by dc impedance. This new electronic parameter of opacity can be related to cell age, since both it and cell age are directly related to buoyant density. This increase in opacity with buoyant density is correlated with a change in shape. 相似文献
75.
M. J. Babiano J. J. Aldasoro J. Hernández-Nistal D. Rodriguez A. Matilla G. Nicolás 《Physiologia plantarum》1984,61(3):391-395
Nonanoic acid, which inhibits germination in several seeds, enhanced ion efflux from embryonic axes of Cicer arietinum L., especially at temperatures above 25°C. Other short chain fatty acids had little effect on germination and ion leakage. Nonanoic acid also decreased uptake of 86 Rb+ and 22 Na+ and increased efflux of both isotopes from the embryonic axes into the incubation solution. Fusicoccin, which stimulates early germination in C. arietinum , counteracted the effects of nonanoic acid at both 25 and 30°C. These results suggest that nonanoic acid affects the integrity of plasmalemma and other membrane systems. Nonanoic acid thus inhibits cell elongation during early germination by disturbing ion exchange and inhibiting water uptake. 相似文献
76.
Julie Marcus 《The Australian journal of anthropology》1987,17(3):185-197
Olive Pink studied anthropology at the University of Sydney under Professor A.P. Elkin. Although she did fieldwork among the Northern Aranda and Wailbri of Central Australia, she became disenchanted with anthropology and lived a reclusive life in Alice Springs. In this paper I present a brief outline of her life, particularly during the 1930's I point to the problems she encountered and suggested that she needs to be relocated within her discipline. 相似文献
77.
G. Gray Eaton Deanne F. Johnson Barbara B. Glick Julie M. Worlein 《Primates; journal of primatology》1986,27(2):141-150
We have quantitatively documented the development of sex differences in the behavior of juvenile Japanese macaques (1 to 2
years of age). Mothers treated their offspring differently by sex, i.e., mothers of males broke contact with them more frequently
than did mothers of females. Juvenile males played more, and mounted other macaques more frequently; juvenile females groomed
their mothers more and were also punished by other group members more frequently than were males. Males showed a pattern of
decreasing interactions with their mothers, but females increased the frequency of their maternal interactions. These patterns
appear to presage the life histories of the sexes. However, comparisons with other species of nonhuman primates indicate that
although sex differences in behavior are common, the variability among species severely limits cross-specific generalizations. 相似文献
78.
Barbara Beckerman Glide G. Gray Eaton Deanne F. Johnson Julie Worlein 《International journal of primatology》1986,7(2):139-155
The behavioral interactions of 22 infant and mother Japanese macaques with other group members were studied. Focal-animal
observations were made from the time of each infant’s birth until 1 year of age. Infants and mothers both displayed exceedingly
strong preferences for associating with matrilineal kin and, specifically, for female kin. The degree of genetic relatedness
was positively correlated with levels of spatial proximity, contact, grooming, aggression, and play. Overall frequencies of
interactions with nonkin were very low, and partner sex was not an important factor in interactions with nonkin. There were
no significant differences between male and female infants in interactions with kin versus nonkin. There was only one significant
difference between male and female infants in interactions with males versus females: female infants showed stronger preferences
for initiating proximity with females over males than did male infants. Because mothers provide the focal point for infant
interactions during the first year of life, we compared the behavior of infants and mothers. Mothers were the recipients of
more social interactions than were infants, mothers engaged in more grooming than did infants, and infants engaged in more
social play than did mothers. These findings are only partially consistent with kin-selection theory, and the inadequacies
of studying matrilineal kin discrimination to test kin selection are reviewed. The near-absence of infant sex differences
in associations with social partners suggests that although maternal kin other than the mother are important to infant socialization,
they probably do not contribute to the development of behavioral sex differences until after the first year of life. 相似文献
79.
Glick Barbara Beckerman Eaton G. Gray Johnson Deanne F. Worlein Julie M. 《International journal of primatology》1986,7(5):467-479
Quantitative data are presented on the effects of subject sex, partner sex,and kinship on the social interactions of 18 juveniles of the Oregon troop of Japanese macaques (Macaca fuscata).Data on these subjects as infants were also used to detail maturational changes in partner sex preferences. Nine males and
nine females, whose multiparous mothers represented a cross section of dominance ranks, were observed using a focal-animal
technique. Juveniles of both sexes engaged in more proximity, contact, grooming, mounting, aggression, and social play with
kin than with nonkin partners. They initiated less contact with females and more contact with males during their second year.
They initiated more grooming and aggression during their second year than their first year, with females displaying a strong
preference for grooming females and males specifically aggressing males more during the second year. Aggression was higher
between same-sexed partners than between opposite-sexed partners. Males engaged in more social interactions with males during
the second year than the first year of life. Males played more than females during both years. Males played more with males
during the second year than the first year, and males played with males more than did females during the second year. We conclude
that sex differences in behavioral frequencies become evident during the first year of life, and sex differences in partner
preferences emerge during the second year of life. 相似文献
80.
Structural and physiological features of sterols necessary to satisfy bulk membrane and sparking requirements in yeast sterol auxotrophs 总被引:10,自引:0,他引:10
A variety of sterols and stanols have been analyzed for their ability to satisfy bulk membrane and high-specificity (sparking) functions in three yeast sterol auxotrophs. While many sterols and stanols satisfied bulk membrane requirements, only those possessing a C-5,6 unsaturation or capable of being desaturated at C-5 fulfilled the high-specificity sparking requirement. Unsaturation of the A-ring or beta-saturation of a C-5,6 double bond rendered both sterol and stanol unsuitable for either function. The C-28 methyl group of ergosterol, while not required for growth, allowed for greater ease of desaturation at C-5 in vivo. As a result some sterols and stanols lacking the C-28 methyl were incapable of satisfying the sparking requirement while identical compounds possessing the C-28 methyl were able to fulfill the sparking function(s). These data are extended to hypothesize a role for the C-28 methyl group of ergosterol in yeast. 相似文献