scholarly journals A CRYSTALLOGRAPHIC STUDY OF PURE CARBONMON-OXIDE HEMOGLOBIN

1930 ◽  
Vol 13 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Alden Kinney Boor
Keyword(s):  
Guinea Pig ◽  
Ethyl Alcohol ◽  
Appreciable Difference ◽  
Crystallographic Study ◽  
Pure Protein ◽  
Suitable Amount ◽  
Species Specific

1. Photomicrographs of crystals of pure carbonmonoxide hemoglobin of the following species are presented; ox, sheep, hog, dog, turkey, rat, horse, chicken and guinea pig. Photomicrographs of the oxyhemoglobin crystals of the following species are also shown: ox, sheep, hog, dog, rat, horse and guinea pig. The crystals were formed from the pure protein by adding a suitable amount of ethyl alcohol and maintaining a temperature of 0°C., or lower. 2. In some species a sufficient difference is shown between the carbonmonoxide hemoglobin and oxyhemoglobin crystals to distinguish these compounds, but the photographs of crystals of carbonmonoxide hemoglobin and oxyhemoglobin of some species, such as guinea pig, show no appreciable difference. 3. Differences between the carbonmonoxide hemoglobins, as well as between the oxyhemoglobins, of the different species studied are indicated. 4. The carbonmonoxide hemoglobin crystals from the bloods studied are species specific in their nature, and, in many cases, can be distinguished from the analogous oxyhemoglobin by crystallographic study.

Developmental changes in passive stiffness and myofilament Ca2+ sensitivity due to titin and troponin-I isoform switching are not critically triggered by birth

2006 ◽  
Vol 291 (2) ◽  
pp. H496-H506 ◽  
Author(s):  
Martina Krüger ◽  
Thomas Kohl ◽  
Wolfgang A. Linke
Keyword(s):  
Guinea Pig ◽  
Heart Development ◽  
Troponin I ◽  
Collagen Matrix ◽  
Passive Stiffness ◽  
Adult Rats ◽  
Functional Changes ◽  
Fetal Rat ◽  
Isoform Switching ◽  
Species Specific

The giant protein titin, a major contributor to myocardial mechanics, is expressed in two main cardiac isoforms: stiff N2B (3.0 MDa) and more compliant N2BA (>3.2 MDa). Fetal hearts of mice, rats, and pigs express a unique N2BA isoform (∼3.7 MDa) but no N2B. Around birth the fetal N2BA titin is replaced by smaller-size N2BA isoforms and N2B, which predominates in adult hearts, stiffening their sarcomeres. Here we show that perinatal titin-isoform switching and corresponding passive stiffness (STp) changes do not occur in the hearts of guinea pig and sheep. In these species the shift toward “adult” proportions of N2B isoform is almost completed by midgestation. The relative contributions of titin and collagen to STp were estimated in force measurements on skinned cardiac muscle strips by selective titin proteolysis, leaving the collagen matrix unaffected. Titin-based STp contributed between 42% and 58% to total STp in late-fetal and adult sheep/guinea pigs and adult rats. However, only ∼20% of total STp was titin based in late-fetal rat. Titin-borne passive tension and the proportion of titin-based STp generally scaled with the N2B isoform percentage. The titin isoform transitions were correlated to a switch in troponin-I (TnI) isoform expression. In rats, fetal slow skeletal TnI (ssTnI) was replaced by adult carciac TnI (cTnI) shortly after birth, thereby reducing the Ca2+ sensitivity of force development. In contrast, guinea pig and sheep coexpressed ssTnI and cTnI in fetal hearts, and skinned fibers from guinea pig showed almost no perinatal shift in Ca2+ sensitivity. We conclude that TnI-isoform and titin-isoform switching and corresponding functional changes during heart development are not initiated by birth but are genetically programmed, species-specific regulated events.

scholarly journals Permissivity of Dipeptidyl Peptidase 4 Orthologs to Middle East Respiratory Syndrome Coronavirus Is Governed by Glycosylation and Other Complex Determinants

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Kayla M. Peck ◽  
Trevor Scobey ◽  
Jesica Swanstrom ◽  
Kara L. Jensen ◽  
Christina L. Burch ◽  
...  
Keyword(s):  
Middle East ◽  
Guinea Pig ◽  
Host Range ◽  
Dipeptidyl Peptidase ◽  
Glycosylation Site ◽  
Middle East Respiratory Syndrome ◽  
Virus Receptor ◽  
Dipeptidyl Peptidase 4 ◽  
Receptor Interactions ◽  
Species Specific

ABSTRACT Middle East respiratory syndrome coronavirus (MERS-CoV) utilizes dipeptidyl peptidase 4 (DPP4) as an entry receptor. While bat, camel, and human DPP4 support MERS-CoV infection, several DPP4 orthologs, including mouse, ferret, hamster, and guinea pig DPP4, do not. Previous work revealed that glycosylation of mouse DPP4 plays a role in blocking MERS-CoV infection. Here, we tested whether glycosylation also acts as a determinant of permissivity for ferret, hamster, and guinea pig DPP4. We found that, while glycosylation plays an important role in these orthologs, additional sequence and structural determinants impact their ability to act as functional receptors for MERS-CoV. These results provide insight into DPP4 species-specific differences impacting MERS-CoV host range and better inform our understanding of virus-receptor interactions associated with disease emergence and host susceptibility. IMPORTANCE MERS-CoV is a recently emerged zoonotic virus that is still circulating in the human population with an ∼35% mortality rate. With no available vaccines or therapeutics, the study of MERS-CoV pathogenesis is crucial for its control and prevention. However, in vivo studies are limited because MERS-CoV cannot infect wild-type mice due to incompatibilities between the virus spike and the mouse host cell receptor, mouse DPP4 (mDPP4). Specifically, mDPP4 has a nonconserved glycosylation site that acts as a barrier to MERS-CoV infection. Thus, one mouse model strategy has been to modify the mouse genome to remove this glycosylation site. Here, we investigated whether glycosylation acts as a barrier to infection for other nonpermissive small-animal species, namely, ferret, guinea pig, and hamster. Understanding the virus-receptor interactions for these DPP4 orthologs will help in the development of additional animal models while also revealing species-specific differences impacting MERS-CoV host range.

Interference with the uptake of guinea-pig agglutinins in mice due to fractions of papain hydrolyzed rabbit γ-globulin

1963 ◽  
Vol 157 (967) ◽  
pp. 160-169 ◽  
Keyword(s):  
Guinea Pig ◽  
Immune Serum ◽  
Rabbit Serum ◽  
Specific Receptor ◽  
Digestion Method ◽  
Suckling Mice ◽  
Absorptive Cells ◽  
Mouse Cells ◽  
Species Specific ◽  
To Receive

Antibodies from immune serum ingested by suckling mice and rats may enter into their circulations. The normal sera of certain species, when mixed with the immune serum administered, reduce the entry of antibodies. This effect was called interference. Interference with the uptake of guinea-pig agglutinins in mice due to rabbit serum and γ-globulin and to fragments I, II and III of rabbit γ-globulin, fractionated by the digestion method of Porter, is investigated. The effect of rabbit serum is due mostly, if not wholly, to its γ-globulin. Interference due to fragments I and II is negligible, whereas interference due to fragment III is at least 3.5 times greater than that due to the whole γ-globulin molecule. It is concluded that most of the configurations of the whole rabbit γ-globulin molecule which are recognized by mouse cells as heterologous are carried on fragment III. A hypothesis, which postulates a specific receptor within absorptive cells concerned with the transmission of antibodies across the gut of some young rodents, is discussed in the light of these results, when it is suggested that the receptor may be better adapted to receive the species-specific parts of antibody molecules rather than the residual or antibody reactive parts.

Molecular basis of species-specific expression of repolarizing K+ currents in the heart

2003 ◽  
Vol 285 (4) ◽  
pp. H1641-H1649 ◽  
Author(s):  
Stephen Zicha ◽  
Isaac Moss ◽  
Bruce Allen ◽  
Andras Varro ◽  
Julius Papp ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Protein Expression ◽  
Guinea Pigs ◽  
Delayed Rectifier ◽  
Important Species ◽  
Α Subunit ◽  
Delayed Rectifier Current ◽  
Mrna Concentration ◽  
Subunit Expression ◽  
Species Specific

There are important species-specific differences in K+ current profiles and arrhythmia susceptibility, but interspecies comparisons of K+ channel subunit expression are lacking. We quantified voltage-gated K+ channel (Kv) subunit mRNA and protein in rabbits, guinea pigs, and humans. Kv1.4, Kv4.2, and Kv4.3 mRNA was present in rabbits but undetectable in guinea pigs. MinK mRNA concentration in guinea pigs was almost threefold greater versus humans and 20-fold versus rabbits. MinK protein expression in guinea pigs was almost twofold that in humans and sixfold that in rabbits. KvLQT1 mRNA concentration was greatest in humans, and protein expression in humans was increased by ∼2- and ∼7-fold compared with values in rabbits and guinea pigs, respectively. The ether-a-go-go-related gene (ERG1) mRNA was more concentrated in humans, but ERG1 protein expression could not be compared across species because of epitope sequence differences. We conclude that important interspecies differences in cardiac K+ channel subunit expression exist and may contribute to the following: 1) lack of a transient outward current in the guinea pig (α-subunit transcription absent in the guinea pig heart); 2) small slow delayed rectifier current and torsades de pointes susceptibility in the rabbit (low-level minK expression); and 3) large slow component of the delayed rectifier current in the guinea pig (strong minK expression).

scholarly journals Mechanisms of hepatic phosphatidylcholine synthesis in the developing guinea pig: contributions of acyl remodelling and of N-methylation of phosphatidylethanolamine

1993 ◽  
Vol 290 (1) ◽  
pp. 67-73 ◽  
Author(s):  
G C Burdge ◽  
F J Kelly ◽  
A D Postle
Keyword(s):  
Fatty Acids ◽  
Guinea Pig ◽  
Molecular Species ◽  
Essential Fatty Acids ◽  
Specific Radioactivity ◽  
Long Chain Fatty Acids ◽  
Radioactivity Analysis ◽  
Species Specific ◽  
Phosphatidylcholine Synthesis

Hepatic phosphatidylcholine (PC) from the immature fetal guinea pig at day 55 of gestation comprised mainly unsaturated molecular species containing C18:2(n-6) and C22:6(n-3) at the sn-2 position, reflecting placental permeability to essential fatty acids. At both day 55 and term (day 68), [Me-14C]choline was incorporated in utero over 3 h largely into sn-1-C16:0 PC species, with incorporation into sn-1-C18:0 PC species increasing by 18 h of incubation. Comparison of specific radioactivities after 3 h and 18 h suggests PC acyl remodelling by phospholipase A1. No incorporation into C20:4(n-6)-containing PC species could be detected of either [Me-14C]choline in vivo or CDP-[Me-14C]choline in isolated microsomes. The major phosphatidylethanolamine (PE) species were 16:0/22:6 and 18:0/22:6. Although [14C]ethanolamine was initially incorporated mainly into sn-1-C16:0 species, specific-radioactivity analysis suggested differential turnover rather than acyl remodelling. [1,2-14C]Ethanolamine and [Me-14C]methionine incorporation into PC molecular species indicated that both newly synthesized and total PE pools were available for N-methylation. Since the PC pool synthesized from PE included C20:4- and C22:6-containing species, N-methylation may provide a mechanism for supplying essential long-chain fatty acids to developing tissues that can be regulated independently from bulk PC synthesis.

scholarly journals The Imaginal Ecdysis of Blowflies. Detection of the Blood-Borne Darkening Factor and Determination of Some of Its properties

1962 ◽  
Vol 39 (3) ◽  
pp. 413-430
Author(s):  
C. B. COTTRELL
Keyword(s):  
Phenolic Compounds ◽  
Organic Solvents ◽  
Ethyl Alcohol ◽  
Room Temperature ◽  
Calliphora Erythrocephala ◽  
Bacterial Protease ◽  
Similar Factor ◽  
The Moment ◽  
Species Specific

1. At the imaginal ecdysis of Calliphora erythrocephala (Meigen) the initiation of normal hardening and darkening is brought about by the release into the blood of an active factor (Cottrell, 1962b). 2. The darkening factor can be detected in fly blood by injecting it into flies decapitated at the moment of emergence. Blood taken from flies at the moment of emergence or 24 hr. after expansion produces little or no reaction, although blood taken between 3 min. and 10 hr. after emergence shows darkening activity. However, extracts of other tissues and many chemicals will also induce darkening though probably unspecifically through damage effects. The assay can therefore be used certainly only for detecting activity in fly blood. 3. The blood-borne darkening factor of blowflies will withstand boiling for 10 min. or drying at 120° C. for 20 min., but it does not retain its activity when kept in solution at room temperature for more than 24 hr. It is non-dialysable, relatively insoluble in organic solvents and is inactivated by ethyl alcohol and the bacterial protease subtilisin. It is probably proteinaceous and is certainly not tyrosine or any of the phenolic compounds at present thought to act as the precursors of the tanning agent. 4. The blood-borne factor of different blowflies (Calliphora, Sarcophaga and Lucilia) is not species-specific and there is some inconclusive evidence that a similar factor is present at the ecdysis of Schistocerca.

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