Acceptability and Feasibility of "Latinos Unidos": A Microgame Resource Combatting Health Misinformation for Latinos Living with HIV.

COVID-19 mitigation strategies, including shelter-in-place orders, masking, and social distancing combined with the widespread "infodemic" may interact synergistically to worsen already compromised mental health outcomes of people living with HIV (PLWH). We developed a three-part microgame intervention, "Latino Unidos," targeting media health literacy education that could be mobilized to protect the mental health of Latinx PLWH as well as promote HIV care during the pandemic. We utilized a community-based approach by working with two local community partners and conducted interviews and focus groups from three perspectives: Latino PLWH, ID providers, and community health workers. Participants evaluated three microgame modules for literacy objectives, acceptability, and feasibility. Feedback offered from each round of module review indicated that each of the game experiences supported the aim of addressing health mis/disinformation. Results indicated relative success demonstrated by positive responses on module literacy goals, acceptability, and feasibility. Our approach illuminates the intersection between content development around media literacy and microgame modality as a novel mHealth resource. Study outcomes offer suggestions and strategies for optimizing content effectiveness and intervention material dissemination.

The Relationship Between Intersectional Oppression and Affirmation and Latino Sexual Minority Men's Mental Health.

Purpose: Latino sexual minority men (LSMM) may experience oppression based on their ethnicity, sexual orientation, and migratory status, yet scientific literature is only beginning to explore the intersection of these experiences. This study examined mental health (MH) in relation to LSMM's experiences of intersectional oppression and affirmation. Methods: We conducted a secondary analysis of baseline data from a cohort study examining LSMM's (n = 290) health care engagement in Miami, FL, from February to September 2020. Latent class analysis (LCA) identified classes based on self-reported multiple identity discrimination (e.g., race, ethnicity, and skin color), sexual orientation stigma/affirmation, and migration-related stress. Logistic and linear regressions examined associations between class membership and anxious, depressive, post-traumatic stress, somatic symptoms, and overall MH burden. Results: The LCA revealed a three-class solution: (1) affirmed LSMM (73.8%), (2) LSMM with intersectional oppression (21.7%), and (3) LSMM with immigration stress (4.5%). The three classes varied in terms of multiple identity discrimination, sexual orientation stigma/affirmation, and migration-related stress. Compared with Class 1, Class 2 had greater conditional probabilities of reporting clinically significant depressive (p = 0.033) and post-traumatic stress symptoms (p = 0.031), and at least one MH concern (p = 0.018). Greater depressive symptoms (p = 0.007), post-traumatic stress symptoms (p = 0.049), somatic symptoms (p = 0.024), and clinically significant MH concerns (p = 0.018) were found among Class 2 than among Class 1. Conclusion: Findings identified three groups of LSMM based on their experiences of intersectional oppression and affirmation. Discrimination at the intersection of multiple identities, sexual orientation stigma/affirmation, and migration-related stress were associated with LSMM's MH outcomes, particularly among immigrants.

Factors associated with latino sexual minority men's likelihood and motivation for obtaining a COVID-19 vaccine: a mixed-methods study.

Minoritized communities are underreached by biomedical interventions, such as the COVID-19 vaccine. This mixed-methods study identified factors associated with vaccine likelihood (VL) and uptake (VU) among 187 Latino sexual minority men (LSMM) in South Florida. Regression models with LASSO variable selection and Classification and Regression Trees (CART) assessed determinants of VL and VU while open-ended questions were evaluated using thematic content analysis. VL (range 1-7; M = 6.00, SD = 1.84) and VU (63.6%) was high. LASSO modeling identified being insured, worrying about others, fear of transmitting COVID-19, and financial stress as the most influential factors for VL; working remotely from home was important for VU. Time (weeks) since addition of COVID-19 vaccination-related questions (December 2nd, 2020) was associated with both outcomes across both modeling techniques. Convergence between data suggests capitalizing on altruistic motivations and improving accessibility to vaccine campaigns are valuable assets to increase LSMM's vaccine confidence.

Engaging Latino sexual minority men in PrEP and behavioral health care: multilevel barriers, facilitators, and potential implementation strategies.

Latino sexual minority men (LSMM) are affected by HIV and behavioral health disparities. Evidence-based HIV-prevention and behavioral health (BH) services are not sufficiently scaled up to LSMM. The current study identified multilevel barriers and facilitators to LSMM's use of HIV-prevention and BH services. LSMM (N = 290) in South Florida, a US HIV epicenter, completed a battery of measures potentially associated with pre-exposure prophylaxis (PrEP) and BH treatment use. Stochastic search variable selection (SSVS) followed by multiple linear regression analyses identified variables associated with engagement in PrEP and BH treatment. Multilevel determinants of PrEP and BH treatment engagement were identified, with most identified determinants being at the relational level (e.g., stigma, discrimination based on income and immigration status, personal recommendation for treatment). Individual (e.g., knowledge, self-efficacy) and structural (e.g., financial stress) determinants were also identified. Accordingly, modifiable leverage points to enhance the reach of PrEP and BH treatment to LSMM include educating and enhancing the perceived relevance of services, de-stigmatizing and normalizing via peer examples, bolstering self-efficacy, and building trust.

Does Problematic Substance Use Moderate Efficacy of Cognitive Behavioral Therapy for Adherence and Depression in HIV?

Problematic substance use may attenuate the effect of treating depression in people living with HIV (PLWH). We examined the potential moderating effect of problematic substance use on depression and adherence outcomes in PLWH (N = 143) who participated in a randomized controlled trial of cognitive behavioral therapy for adherence and depression (CBT-AD) and were randomized to either CBT-AD or enhanced treatment as usual (ETAU). Problematic substance use was operationalized as either having substance use-related diagnosis or current substance use in the past 30 days with a lifetime history of problematic use. Acute (baseline to 4-month) and follow up (4, 8, and 12-month) general linear modeling with time, condition, problematic baseline substance use, and corresponding interactions demonstrated that substance use did not significantly moderate the effects of CBT-AD on adherence or depression improvements. Therefore, CBT-AD was beneficial for PLWH with depression, regardless of problematic substance use when starting depression treatment. Based on these results, clinicians should not withhold CBT treatment for depression in patients with HIV and problematic substance use to attain reductions in depression and gains in adherence.

Refining an Implementation Strategy to Enhance the Reach of HIV-Prevention and Behavioral Health Treatments to Latino Men Who Have Sex with Men.

Background: Latino men who have sex with men (LMSM) experience HIV and behavioral health disparities. Yet, evidence-based interventions, such as pre-exposure prophylaxis (PrEP) and behavioral health treatments, have not been equitably scaled up to meet LMSM needs. To address quality of life and the public health importance of HIV prevention, implementation strategies to equitably scale up these interventions to LMSM need to be developed. This study identifies themes for developing culturally grounded implementation strategies to increase uptake of evidence-based HIV prevention and behavioral health treatments among LMSM. Methods: Participants included 13 LMSM and 12 stakeholders in Miami, an HIV epicenter. Feedback regarding the content, design, and format of an implementation strategy to scale up HIV-prevention and behavioral health services to LMSM were collected via focus groups (N=3) and individual interviews (N=3). Themes were inductively identified across the Health Equity Implementation Framework (HEIF) domains. Results: Analyses revealed five higher order themes regarding the design, content, and format of the implementation strategy: cultural context, relationships and networks, navigation of health information and systems, resources and models of service delivery, and motivation to engage. Themes were applicable across HEIF domains, meaning that the same theme could have implications for both the development and implementation of the implementation strategy. Conclusions: Findings highlight the importance of addressing culturally specific factors, leveraging relational networks, facilitating navigation of health systems, tailoring to available resources, and building consumer and implementer motivation in order to refine an implementation strategy for reducing mental health burden and achieving HIV health equity among LMSM.

A Relational Framework for Engaging Latino Sexual Minority Men in Sexual and Behavioral Health Research.

Latino sexual minority men (LSMM) experience sexual and behavioral health disparities. Yet, LSMM are underrepresented in sexual and behavioral health research, creating scientific inequity. There is, therefore, a need to identify the barriers and facilitators to LSMM's participation in sexual and behavioral health research, which is the gap that the current study sought to fill. We interviewed LSMM (n = 28; age 18-40, 57% US born) and key informants (n = 10) regarding LSMM's barriers and facilitators to participating in sexual and behavioral health research and suggestions for increasing participation. The research team coded the data via thematic analysis. We found that relational factors are central to understanding LSMM's participation in sexual and behavioral health research. Some relational experiences (e.g., interpersonal stigma) interfered with participation, whereas others (e.g., altruistic desires to contribute to community well-being) facilitated participation. The findings are consolidated within a new relational framework for understanding LSMM's participation in sexual and behavioral health research. Study findings highlight the centrality of relational factors in influencing LSMM's participation in sexual and behavioral health research. Relational factors can be used to inform the development of culturally relevant recruitment strategies to improve representation of LSMM in sexual and behavioral health research. Implementing these recommendations may address scientific inequity, whereby LSMM are disproportionately impacted by sexual and behavioral health concerns yet underrepresented in related research.

Latinx Sexual Minority Men's Access to HIV and Behavioral Health Services in South Florida During COVID-19: A Qualitative Study of Barriers, Facilitators, and Innovations.

ABSTRACT: Despite the availability of HIV prevention and treatment tools, HIV disparities continue to affect Latinx sexual minority men (LSMM). Behavioral health concerns further exacerbate HIV disparities among LSMM. This study used rapid qualitative analysis to understand factors influencing LSMM's access to HIV and behavioral health services during coronavirus disease 2019 (COVID-19). Participants included LSMM with (n = 10) and without HIV (n = 10). The analysis identified 15 themes. Themes revealed that LSMM's access was disrupted by new and worsening barriers resulting from COVID-19, such as anxiety about COVID-19 exposure, confusion and disruptions to services, and new structural challenges. Other themes highlight positive changes, such as telehealth and relaxed clinic protocols, which enhanced LSMM's access to services during COVID-19. The findings suggest the need for HIV and behavioral health clinics to innovate and ensure LSMM's continued access to services during and beyond COVID-19.

Latinx Sexual Minority Men's Behavioral, Psychosocial, and Medical Experiences during COVID-19: Differences across Immigration Statuses.

Latinx sexual minority men (LSMM) are at the intersection of two communities disproportionately impacted by COVID-19. To develop and deploy appropriate resources to support LSMM, it is important to understand the behavioral, psychosocial, and medical experiences of this population during COVID-19, as well as for LSMM of different immigration statuses. The current study uses the Pandemic Stress Index (PSI) to describe LSMM's self-reported behavioral, psychosocial, and medical experiences during COVID-19. Logistic and linear regressions compared experiences during COVID-19 among LSMM across different immigration statuses (recent, established, and US-born as the reference group). LSMM's responses to the PSI indicated they experienced anxiety (64.4%), depression (59.0%), alcohol/substance use (27.6%), as well as loneliness (50.1%) and sleep problems (60.4%). Overall, over half reported personal financial loss, the odds of which were 2.75 times greater among LSMM who were recent immigrants compared to US-born LSMM (OR = 2.75, 95% CI: 1.30, 5.82). Nearly 8% reported being diagnosed with COVID-19, with the odds four and a half times greater among established immigrants compared to US-born LSMM (OR = 4.52, 95% CI: 1.60, 12.81). The findings have implications for tailored support resources and public health interventions to reach LSMM in general and LSMM with immigration histories.

Scaling Up and Out HIV Prevention and Behavioral Health Services to Latino Sexual Minority Men in South Florida: Multi-Level Implementation Barriers, Facilitators, and Strategies.

Latino sexual minority men (LSMM) are disproportionately affected by HIV in the United States. Concurrently, behavioral health disparities, including mental health and substance use concerns, worsen HIV disparities affecting LSMM. Yet, evidence-based HIV prevention and behavioral health services are insufficiently scaled up and out to this population, perpetuating health disparities, thwarting efforts to control the HIV epidemic, and highlighting the need for culturally relevant evidence-based implementation strategies that address these disparities. Participants included 28 LSMM with varying degrees of engagement in HIV prevention and behavioral health services, and 10 stakeholders with experience delivering HIV prevention and behavioral health services to LSMM in South Florida, an HIV epicenter in general and in particular for LSMM. Participants completed semistructured interviews (English/Spanish) regarding LSMM's barriers and facilitators to engaging in HIV prevention and behavioral health services. Interviews were audio recorded and analyzed using thematic analysis. The 16 themes that emerged from the qualitative analysis were consistent with the consolidated framework for implementation research, an implementation research framework that articulates barriers and facilitators to implementing clinical interventions. Findings suggested the need for implementation strategies that simplify and reduce costs of HIV prevention and behavioral health services, address syndemic challenges impacting service use among LSMM, reduce stigma about service utilization, leverage peer networks, increase provider and community knowledge about services, and build LSMM's readiness and motivation to engage in services. Such strategies may ultimately address HIV and behavioral health disparities among LSMM and facilitate achievement of ending the HIV epidemic goals in this disproportionally affected population.

Interventions Addressing Depression and HIV-Related Outcomes in People with HIV.

PURPOSE OF REVIEW: People with HIV (PWH) are more likely to experience depression than those without HIV. Depression is not only distressing and interfering in and of itself, but it is also consistently associated with non-adherence to antiretroviral treatment (ART). Accordingly, research and clinical priorities require updated knowledge about interventions that address depression in PWH. RECENT FINDINGS: Twenty efficacy trials and nine pilot studies since a 2009 review emerged in the literature review search. Of these, 11 and 6 respectively had a depression-related inclusion criterion. The intervention strategies included individual psychotherapy (n=6), group therapy (n=6), telehealth (n=3), and antidepressant medication (n=5). Generally, these interventions demonstrated acute efficacy for improving depression symptoms in PWH, with some also addressing ART non-adherence. However, not all studies collected follow-up data. Furthermore, trials that addressed depression but did not specifically address non-adherence did not also show adherence improvements. Existing interventions for depression have demonstrated efficacy in PWH, and these may have both positive mental and physical health outcomes. Future trials should measure and boost longer-term effects. It would be useful to incorporate adherence interventions into depression treatment to improve self-care behaviors and health outcomes.

Who Aren't We Reaching? Young Sexual Minority Men's Non-participation in an HIV-Prevention and Mental Health Clinical Trial.

Despite many successful clinical trials to test HIV-prevention interventions for sexual minority men (SMM), not all SMM are reached by these trials. Identifying factors associated with non-participation in these trials could help to ensure the benefits of research extend to all SMM. Prospective participants in New York City and Miami were screened to determine eligibility for a baseline assessment for a mental health/HIV-prevention trial (N = 633 eligible on screen). Logistic regression and classification and regression tree (CART) analysis identified predictors of non-participation in the baseline, among those who were screened as eligible and invited to participate. Individuals who reported unknown HIV status were more likely to be non-participators than those who reported being HIV-negative (OR = 2.39; 95% CI 1.41, 4.04). In New York City, Latinx SMM were more likely to be non-participators than non-Latinx white SMM (OR = 1.81; 95% CI, 1.09, 2.98). A CART model pruned two predictors of non-participation: knowledge of HIV status and age, such that SMM with unknown HIV status and SMM ages 18-19 were less likely to participate. Young SMM who did not know their HIV status, and thus are more likely to acquire and transmit HIV, were less likely to participate. Additionally, younger SMM (18-19 years) and Latinx SMM in New York City were less likely to participate. The findings suggest the importance of tailored recruitment to ensure HIV-prevention/mental health trials reach all SMM.

RESUMEN: A pesar de muchos ensayos clínicos exitosos para probar intervenciones de prevención del VIH para hombres de minorías sexuales (HMS), no todos los HMS son alcanzados por estos ensayos. La identificación de factores asociados con la no participación en estos ensayos podría ayudar a asegurar que los beneficios de la investigación se extiendan a todos los HMS. Se realizaron evaluaciones de teléfono para determinar la elegibilidad para la visita inicial para un ensayo de salud mental/prevención del VIH (N = 633 elegibles en las evaluaciones). La regresión logística y el análisis de arboles de regresión y clasificación (ARC) identificaron predictores de no participación en la visita inicial, entre aquellos que fueron evaluados como elegibles e invitados a participar. Los individuos que reportaron estado desconocido de VIH fueron más probables a ser no participantes que aquellos que reportaron ser VIH negativos (RP = 2.39; IC 95% 1.41, 4.04). En la ciudad de Nueva York, HMS latinx eran más probable a no participar que los HMS blancos no latinx (RP = 1.81; IC 95%, 1.09, 2.98). Un modelo de ARC podó dos predictores de no participación: el conocimiento del estado de VIH y la edad, tal que los HMS con estado desconocido del VIH y las HMS de 18­19 años eran menos probables a participar. Los HMS jóvenes que no conocían su estado de VIH, y por lo tanto eran más probables a adquirir y transmitir el VIH, tenían menos probabilidades de participar. Además, las HMS más jóvenes (18­19 años) y los HMS latinx en la ciudad de Nueva York eran menos probables a participar. Los resultados sugieren la importancia de un reclutamiento personalizado para garantizar que los ensayos de prevención del VIH y salud mental lleguen a todos los SMM.

Assessing topology and surface orientation of an antimicrobial peptide magainin 2 using mechanically aligned bilayers and electron paramagnetic resonance spectroscopy.

Aligned CW-EPR membrane protein samples provide additional topology interactions that are absent from conventional randomly dispersed samples. These samples are aptly suited to studying antimicrobial peptides because of their dynamic peripheral topology. In this study, four consecutive substitutions of the model antimicrobial peptide magainin 2 were synthesized and labeled with the rigid TOAC spin label. The results revealed the helical tilts to be 66°â€¯±â€¯5°, 76°â€¯±â€¯5°, 70°â€¯±â€¯5°, and 72°â€¯±â€¯5° for the TOAC substitutions H7, S8, A9, and K10 respectively. These results are consistent with previously published literature. Using the EPR (electron paramagnetic resonance) mechanical alignment technique, these substitutions were used to critically assess the topology and surface orientation of the peptide with respect to the membrane. This methodology offers a rapid and simple approach to investigate the structural topology of antimicrobial peptides.

Probing topology and dynamics of the second transmembrane domain (M2δ) of the acetyl choline receptor using magnetically aligned lipid bilayers (bicelles) and EPR spectroscopy.

Characterizing membrane protein structure and dynamics in the lipid bilayer membrane is very important but experimentally challenging. EPR spectroscopy offers a unique set of techniques to investigate a membrane protein structure, dynamics, topology, and distance constraints in lipid bilayers. Previously our lab demonstrated the use of magnetically aligned phospholipid bilayers (bicelles) for probing topology and dynamics of the membrane peptide M2δ of the acetyl choline receptor (AchR) as a proof of concept. In this study, magnetically aligned phospholipid bilayers and rigid spin labels were further utilized to provide improved dynamic information and topology of M2δ peptide. Seven TOAC-labeled AchR M2δ peptides were synthesized to demonstrate the utility of a multi-labeling amino acid substitution alignment strategy. Our data revealed the helical tilts to be 11°, 17°, 9°, 17°, 16°, 11°, 9°±4° for residues I7TOAC, Q13TOAC, A14TOAC, V15TOAC, C16TOAC, L17TOAC, and L18TOAC, respectively. The average helical tilt of the M2δ peptide was determined to be ∼13°. This study also revealed that the TOAC labels were attached to the M2δ peptide with different dynamics suggesting that the sites towards the C-terminal end are more rigid when compared to the sites towards the N-terminus. The dynamics of the TOAC labeled sites were more resolved in the aligned samples when compared to the randomly disordered samples. This study highlights the use of magnetically aligned lipid bilayer EPR technique to determine a more accurate helical tilt and more resolved local dynamics of AchR M2δ peptide.

Determining the Secondary Structure of Membrane Proteins and Peptides Via Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy.

Revealing detailed structural and dynamic information of membrane embedded or associated proteins is challenging due to their hydrophobic nature which makes NMR and X-ray crystallographic studies challenging or impossible. Electron paramagnetic resonance (EPR) has emerged as a powerful technique to provide essential structural and dynamic information for membrane proteins with no size limitations in membrane systems which mimic their natural lipid bilayer environment. Therefore, tremendous efforts have been devoted toward the development and application of EPR spectroscopic techniques to study the structure of biological systems such as membrane proteins and peptides. This chapter introduces a novel approach established and developed in the Lorigan lab to investigate membrane protein and peptide local secondary structures utilizing the pulsed EPR technique electron spin echo envelope modulation (ESEEM) spectroscopy. Detailed sample preparation strategies in model membrane protein systems and the experimental setup are described. Also, the ability of this approach to identify local secondary structure of membrane proteins and peptides with unprecedented efficiency is demonstrated in model systems. Finally, applications and further developments of this ESEEM approach for probing larger size membrane proteins produced by overexpression systems are discussed.

Architecture of the fungal nuclear pore inner ring complex.

The nuclear pore complex (NPC) constitutes the sole gateway for bidirectional nucleocytoplasmic transport. We present the reconstitution and interdisciplinary analyses of the ~425-kilodalton inner ring complex (IRC), which forms the central transport channel and diffusion barrier of the NPC, revealing its interaction network and equimolar stoichiometry. The Nsp1•Nup49•Nup57 channel nucleoporin heterotrimer (CNT) attaches to the IRC solely through the adaptor nucleoporin Nic96. The CNT•Nic96 structure reveals that Nic96 functions as an assembly sensor that recognizes the three-dimensional architecture of the CNT, thereby mediating the incorporation of a defined CNT state into the NPC. We propose that the IRC adopts a relatively rigid scaffold that recruits the CNT to primarily form the diffusion barrier of the NPC, rather than enabling channel dilation.

Enhancement of electron spin echo envelope modulation spectroscopic methods to investigate the secondary structure of membrane proteins.

This paper reports on a significant improvement of a new structural biology approach designed to probe the secondary structure of membrane proteins using the pulsed EPR technique of electron spin echo envelope modulation (ESEEM) spectroscopy. Previously, we showed that we could characterize an α-helical secondary structure with ESEEM spectroscopy using a (2)H-labeled Val side chain coupled with site-directed spin-labeling (SDSL). In order to further develop this new approach, molecular dynamic (MD) simulations were conducted on several different hydrophobic residues that are commonly found in membrane proteins. (2)H-SL distance distributions from the MD results indicated that (2)H-labeled Leu was a very strong candidate to significantly improve this ESEEM approach. In order to test this hypothesis, the secondary structure of the α-helical M2δ peptide of the acetylcholine receptor (AChR) incorporated into a bicelle was investigated with (2)H-labeled Leu d(10) at position 10 (i) and nitroxide spin labels positioned 1, 2, 3, and 4 residues away (denoted i+1 to i+4) with ESEEM spectroscopy. The ESEEM data reveal a unique pattern that is characteristic of an α-helix (3.6 residues per turn). Strong (2)H modulation was detected for the i+3 and i+4 samples, but not for the i+2 sample. The (2)H modulation depth observed for (2)H-labeled d(10) Leu was significantly enhanced (×4) when compared to previous ESEEM measurements that used (2)H-labeled d(8) Val. Computational studies indicate that deuterium nuclei on the Leu side chain are closer to the spin label when compared to Val. The enhancement of (2)H modulation and the corresponding Fourier Transform (FT) peak intensity for (2)H-labeled Leu significantly reduces the ESEEM data acquisition time for Leu when compared to Val. This research demonstrates that a different (2)H-labeled amino acid residue can be used as an efficient ESEEM probe further substantiating this important biophysical technique. Finally, this new method can provide pertinent qualitative structural information on membrane proteins in a short time (few minutes) at low sample concentrations (~50 µM).

Distance measurements on a dual-labeled TOAC AChR M2δ peptide in mechanically aligned DMPC bilayers via dipolar broadening CW-EPR spectroscopy.

A membrane alignment technique has been used to measure the distance between two TOAC nitroxide spin labels on the membrane-spanning M2δ, peptide of the nicotinic acetylcholine receptor (AChR), via CW-EPR spectroscopy. The TOAC-labeled M2δ peptides were mechanically aligned using DMPC lipids on a planar quartz support, and CW-EPR spectra were recorded at specific orientations. Global analysis in combination with rigorous spectral simulation was used to simultaneously analyze data from two different sample orientations for both single- and double-labeled peptides. We measured an internitroxide distance of 14.6 Šfrom a dual TOAC-labeled AChR M2δ peptide at positions 7 and 13 that closely matches with the 14.5 Šdistance obtained from a model of the labeled AChR M2δ peptide. In addition, the angles determining the relative orientation of the two nitroxides have been determined, and the results compare favorably with molecular modeling. The global analysis of the data from the aligned samples gives much more precise estimates of the parameters defining the geometry of the two labels than can be obtained from a randomly dispersed sample.

Probing the helical tilt and dynamic properties of membrane-bound phospholamban in magnetically aligned bicelles using electron paramagnetic resonance spectroscopy.

Wild-type phospholamban (WT-PLB), a Ca(2+)-ATPase (SERCA) regulator in the sarcoplasmic reticulum membrane, was studied using TOAC nitroxide spin labeling, magnetically aligned bicelles, and electron paramagnetic resonance (EPR) spectroscopy to ascertain structural and dynamic information. Different structural domains of PLB (transmembrane segment: positions 42 and 45, loop region: position 20, and cytoplasmic domain: position 10) were probed with rigid TOAC spin labels to extract the transmembrane helical tilt and structural dynamic information, which is crucial for understanding the regulatory function of PLB in modulating Ca(2+)-ATPase activity. Aligned experiments indicate that the transmembrane domain of wild-type PLB has a helical tilt of 13°±4° in DMPC/DHPC bicelles. TOAC spin labels placed on the WT-PLB transmembrane domain showed highly restricted motion with more than 100ns rotational correlation time (τ(c)); whereas the loop, and the cytoplasmic regions each consists of two distinct motional dynamics: one fast component in the sub-nanosecond scale and the other component is slower dynamics in the nanosecond range.